随手记

同事们，

以下是我 16 Jun 2020 的每日汇总：

我昨天完成了什么？


我今天计划做什么？


我遇到了什么阻碍？


目前没有任何会议计划！

The confirmation key (English: carriage return), often abbreviated as CR, refers to the control character or process of resetting the positioning device to the beginning of the text line, used to reset the position of a device to the beginning of a line of words. Originally, the term confirm key was used for the typewriter’s wrench. If the language of the typewriter is written from left to right. Enter is used to move the carriage carrying the paper loading roller to the far right, so that the printing position is aligned with the beginning of a line, and at the same time, the roller is rotated to the next line. The first powered return function was added to the electric typewriter by Smith Corona in 1960. This key is generally marked as carriage return or return. If the keyboard is for non-English-speaking countries, the confirmation key will be represented by the ↵ (U+21B5, ↵) symbol, so that the function of this key can be explained directly in the image.

回车符
确认键（英语：carriage return），常缩写为CR，是指将定位设备重置到文本行首的控制字符或过程，用以把一设备的位置重设到一行字的头。 原本，确认键这术语用于打字机的板手。若打字机的语言由左至右书写的语言．回车用于将承载装纸滚筒的机架（carriage）移到最右边，以便令印字位置对准一行的开头，同时顺便转动滚筒，换至下一行。第一个有动力的回车功能是是在1960年由Smith Corona加入电打字机中，此键一般会标示为carriage return或return。 若是针对非英语系国家的键盘，确认键会用↵（U+21B5、↵）符号表示，如此可以在直接用图像方式说明此键的功能

markup: Markup 英语
Markup can refer to:
Markup language, a notation used to annotate a document’s content to give information regarding the structure of the text or instructions for how it is to be displayed.
“Markup business”, a kind of service in ICT context, to markup refers to a service of “marking-up” a free text into a marked one, for a specific markup language.
Markup (business) a term in Economy, for the increase in the price of goods to create a profit margin for a business Markup (legislation), a legislative session held to amend bills

In generale un linguaggio di markup è un insieme di regole che descrivono i meccanismi di rappresentazione (strutturali, semantici o presentazionali) di un testo che, utilizzando convenzioni standardizzate, sono utilizzabili su più supporti. La tecnica di formattazione per mezzo di marcatori (o espressioni codificate) richiede quindi una serie di convenzioni, ovvero appunto di un linguaggio a marcatori di documenti.
Descrizione Il termine markup (o marcatura) deriva dall’ambiente tipografico dove si usava marcare con annotazioni le parti del testo che andavano evidenziate o corrette, allo scopo di segnalarle al compositore o al dattilografo. Tipologie I diversi linguaggi di markup esistenti si distinguono fondamentalmente in: linguaggi di markup di tipo procedurale; linguaggi di markup di tipo descrittivo.
La differenza tra i due sta nel meccanismo usato per definire la rappresentazione del testo, sia per quanto riguarda la sua struttura, sia per quanto riguarda il significato degli elementi che lo compongono, sia per quanto riguarda la visualizzazione (o formattazione): i linguaggi di markup di tipo procedurale indicano le procedure di trattamento del testo aggiungendo le istruzioni che devono essere eseguite per visualizzare la porzione di testo referenziata (troff, TEX, …) i linguaggi di markup di tipo descrittivo lasciano la scelta del tipo di rappresentazione da applicare al testo al software che di volta in volta lo riprodurrà (SGML, HTML, XML, …) I linguaggi del secondo tipo risultano più vantaggiosi perché si concentrano sui problemi strutturali di leggibilità e prescindono in fase di lettura dal software con cui sono stati generati. Sono, in altre parole, quelli che permettono di garantire una corretta separazione tra struttura e visualizzazione (o presentazione, non necessariamente visuale: ad esempio, parlata). L’SGML (Standard Generalized Markup Language) è stato il primo metalinguaggio di markup descrittivo standardizzato a livello internazionale (ISO 8879 del 1986) che ha definito dei metodi di rappresentazione del testo in forma elettronica in modo indipendente dall’hardware e dal sistema utilizzato. L’SGML è basato sul concetto di definizione del tipo di documento o Document Type Definition (DTD) ovvero richiede per ogni documento la definizione del modo in cui i vari elementi del testo possono essere utilizzati. Ad esempio una lettera contiene degli elementi essenziali quali mittente, uno o più destinatari, data, oggetto, corpo, l’indicazione di colui che la firma, … Tutti elementi che devono essere presenti, probabilmente anche con un certo ordine. La DTD deve prendersi carico di definire tutto questo, stabilendo ciò che è permesso e cosa invece non lo è. Voci correlate Linguaggi della famiglia SGML SGML HTML Linguaggi della famiglia XML XML XAML Extensible Stylesheet Language: XSL-T, XSL-FO, XPath, XPointer, XQuery, RelaxNG XPDL PMML Scalable Vector Graphics Resource Description Framework, RDFS, OWL, DAML+OIL XHTML DocBook Voicexml Linguaggi leggeri AFT AsciiDoc BBCode Creole Deplate Markdown Mediawiki PmWiki POD reStructuredText Textile Texi! txt2tags Altri linguaggi JSON CSS LaTeX TeX TROFF Rich Text Format Document Style Semantics and Specification Language AIML Markup

网络释义
标记 :英语百科 标记可以参考：
标记语言，一种用于注释文档内容的注释，以提供有关文本结构的信息或如何显示文本的说明。
用于标记的“标记业务”是一种在ICT上下文中的服务，是指针对特定标记语言将免费文本“标记”为标记文本的服务。
标记（商业）在经济中的一个术语，指商品价格的上涨为商业创造利润
标记（立法），为修改法案而举行的立法会议

通常，标记语言是描述文本表示机制（结构，语义或表示形式）的一组规则，使用标准化的约定，可以在多种支持上使用文本。因此，借助于标记（或编码表达式）的格式化技术需要一系列约定，即具有文档标记的语言。

标记（或标记）一词源自印刷环境，在印刷环境中，它用于用注释标记必须加亮或更正的文本部分，以便将其报告给作曲家或打字员。

现有的不同标记语言基本上分为：
程序标记语言；
描述性标记语言。
两者之间的区别在于用于定义文本表示的机制，既涉及文本的结构，也涉及构成文本的元素的含义，以及涉及显示（或格式）：程序标记语言通过添加显示被引用文本的一部分（troff，TEX，…）必须执行的指令来指示文本处理过程
描述性标记语言将选择要应用于文本的表示形式的选择留给软件，该软件将不时地复制文本（SGML，HTML，XML等）
第二种类型的语言更具优势，因为它们专注于可读性的结构性问题，并且在阅读时忽略了生成它们的软件。换句话说，它们是允许在结构和可视化（或表示形式，不一定是视觉：例如口头表达）之间正确分离的语言。

SGML（标准通用标记语言）是第一个国际标准化的描述性标记语言（1986年的ISO 8879），它定义了独立于所使用的硬件和系统以电子形式表示文本的方法。

SGML基于文档类型定义或文档类型定义（DTD）的概念，或者要求每个文档都定义如何使用文本的各种元素的定义。例如，一封信包含必不可少的要素，例如发件人，一个或多个收件人，日期，主题，正文，签名人的指示……。

所有必须存在的要素，也可能以一定顺序存在。 DTD必须小心定义所有这一切，确定允许的内容和不允许的内容。

Reference
SGML家族的语言
SGML
的HTML
XML家族的语言
XML格式
XAML
可扩展样式表语言：XSL-T，XSL-FO，XPath，XPointer，XQuery，RelaxNG
XPDL
PMML
可缩放矢量图形
资源描述框架，RDFS，OWL，DAML + OIL
XHTML
DocBook
语音XML
轻语
国库署
AsciiDoc
BB代码
克里奥尔语
镀层
降价促销
媒体维基
维基百科
荚
reStructuredText
纺织品
特喜！
txt2标签
其他语言
JSON格式
的CSS
胶乳
TeX
TROFF
富文本格式
文档样式语义和规范语言
艾美

C → c (lower case — first level)
⇧ Shift+C → C (upper case — second level)
AltGr+C → © (copyright sign — third level)
AltGr+⇧ Shift+C → ¢ (cent sign — fourth level)

box-drawing characters

Norton Commander using box-drawing characters in Win32 console Box-drawing characters, also known as line-drawing characters, are a form of semigraphics widely used in text user interfaces to draw various geometric frames and boxes. In graphical user interfaces, these characters are much less useful as it is much simpler to draw lines and rectangles directly with graphical APIs. Box-drawing characters work only with monospaced fonts; however, they are still useful for plaintext comments on websites. Used along with box-drawing characters are block elements, shade characters, and terminal graphic characters. These can be used for filling regions of the screen and portraying drop shadows. Encodings Unicode Unicode includes 128 such characters. In many Unicode fonts only the subset that is also available in the PC character set (see below) will exist, due to it being defined as part of the WGL4 character set. Unicode box-drawing symbols. A rendering showing all 128 symbols (as they should appear in the chart at left) Box Drawing Official Unicode Consortium code chart (PDF) 0 1 2 3 4 5 6 7 8 9 A B C D E F U+250x ─ ━ │ ┃ ┄ ┅ ┆ ┇ ┈ ┉ ┊ ┋ ┌ ┍ ┎ ┏ U+251x ┐ ┑ ┒ ┓ └ ┕ ┖ ┗ ┘ ┙ ┚ ┛ ├ ┝ ┞ ┟ U+252x ┠ ┡ ┢ ┣ ┤ ┥ ┦ ┧ ┨ ┩ ┪ ┫ ┬ ┭ ┮ ┯ U+253x ┰ ┱ ┲ ┳ ┴ ┵ ┶ ┷ ┸ ┹ ┺ ┻ ┼ ┽ ┾ ┿ U+254x ╀ ╁ ╂ ╃ ╄ ╅ ╆ ╇ ╈ ╉ ╊ ╋ ╌ ╍ ╎ ╏ U+255x ═ ║ ╒ ╓ ╔ ╕ ╖ ╗ ╘ ╙ ╚ ╛ ╜ ╝ ╞ ╟ U+256x ╠ ╡ ╢ ╣ ╤ ╥ ╦ ╧ ╨ ╩ ╪ ╫ ╬ ╭ ╮ ╯ U+257x ╰ ╱ ╲ ╳ ╴ ╵ ╶ ╷ ╸ ╹ ╺ ╻ ╼ ╽ ╾ ╿ Notes 1.^ As of Unicode version 8.0 DOS The original IBM PC supplied the following box-drawing characters, in what MS-DOS now calls code page 437. This subset of the Unicode box-drawing characters is thus far more popular and likely to be rendered correctly: 0 1 2 3 4 5 6 7 8 9 A B C D E F B │ ┤ ╡ ╢ ╖ ╕ ╣ ║ ╗ ╝ ╜ ╛ ┐ C └ ┴ ┬ ├ ─ ┼ ╞ ╟ ╚ ╔ ╩ ╦ ╠ ═ ╬ ╧ D ╨ ╤ ╥ ╙ ╘ ╒ ╓ ╫ ╪ ┘ ┌ Their number is further limited to 22 on those code pages that replace the 18 “single/double hybrid” characters for other, usually alphabetic, characters (such as code page 850): 0 1 2 3 4 5 6 7 8 9 A B C D E F B │ ┤ ╣ ║ ╗ ╝ ┐ C └ ┴ ┬ ├ ─ ┼ ╚ ╔ ╩ ╦ ╠ ═ ╬ D ┘ ┌ Note: The non-double characters are the “thin” ones (U+2500, U+2502), not the “wide” ones (U+2501, U+2503). Unix, CP/M, BBS On many Unix systems and early dial-up bulletin board systems the only common standard for box-drawing characters was the VT100 alternate character set. The escape sequence Esc ( 0 switched the codes for lower-case ASCII letters to draw this set, and the sequence Esc ( B switched back: 0 1 2 3 4 5 6 7 8 9 A B C D E F 6 ┘ ┐ ┌ └ ┼ 7 ─ ├ ┤ ┴ ┬ │ A Bash script that displays all of the semigraphic characters: char=( 6a 6b 6c 6d 6e 71 74 75 76 77 78 ) for i in $char[\ast ]doprintf"0x$i \xKaTeX parse error: Undefined control sequence: \e at position 3: i \̲e̲(0\xi\e(B\n" done On some terminals, these characters are not available at all, and the complexity of the escape sequences discouraged their use, so often only ASCII characters that approximate box-drawing characters are used, such as - (hyphen-minus), | (vertical bar), _ (underscore), = (equal sign) and + (plus sign) in a kind of ASCII art fashion. Modern Unix terminal emulators use Unicode and thus have access to the line-drawing characters listed above. Historical Many microcomputers of the 1970s and 1980s had their own proprietary character sets, which also included box-drawing characters. Some of these sets, such as Commodore’s PETSCII, include box-drawing symbols with no corresponding Unicode character. ZX81 semigraphics The Sinclair ZX81 and Spectrum included a set of text semigraphics with block elements and dithering patterns. The BBC Micro could utilise the Teletext 7-bit character set, which had 128 box-drawing characters, whose code points were shared with the regular alphanumeric and punctuation characters. Control characters were used to switch between regular text and box drawing. MouseText is a set of display characters for the Apple IIc, IIe, and IIgs that includes box-drawing characters. Some recent embedded systems also use proprietary character sets, usually extensions to ISO 8859 character sets, which include box-drawing characters or other special symbols. The World Standard Teletext (WST) uses pixel-drawing characters for some graphics. A character cell is divided in 2×3 regions, and 2 = 64 code positions are allocated for all possible combinations of “pixels”. However, these characters are not included in the Unicode standard.
第2次查询
网络释义
参考翻译 [复制]
诺顿指挥官在Win32控制台中使用绘图字符
方框图字符，也称为线条图字符，是一种半图形形式，广泛用于文本用户界面中以绘制各种几何框架和方框。在图形用户界面中，这些字符的用处不大，因为使用图形API直接绘制线条和矩形要简单得多。箱形绘图字符仅适用于等宽字体；但是，它们仍可用于网站上的纯文本注释。
与方框图字符一起使用的是块元素，阴影字符和终端图形字符。这些可用于填充屏幕区域和描绘阴影。
编码方式
统一码
Unicode包含128个此类字符。在许多Unicode字体中，仅存在PC字符集中可用的子集（请参见下文），因为它被定义为WGL4字符集的一部分。

Unicode方框图符号。显示所有128个符号的渲染图（它们应显示在左侧的图表中）
箱形图
官方Unicode联盟代码表（PDF）
0 1 2 3 4 5 6 7 8 9 A B C D E F
U + 250x─━│││┄┆┏┏┎
U + 251x├├├├├├
U + 252x +┣┤┪┮
U + 253x +┲┴┺┾┾
U + 254x +╃╅╏╎╎
U + 255x +╓╔╟╞
U + 256x╩╩╨╩╩╩╩╩
U + 257x╱╱╱╱╱╱╾╾
笔记

1. ^自Unicode版本8.0起
   DOS
   原始的IBM PC提供了以下方框图字符，现在MS-DOS称为代码页437。Unicode方框图字符的这个子集因此更加流行并且可以正确呈现：
   0 1 2 3 4 5 6 7 8 9 A B C D E F
   B││╢╛╛
   C└┬├─┼╩╩╩╩╩╩
   d╨╤╥╙╘╒╓╫╪┘┌
   在那些用18个“单/双混合”字符替换其他通常是字母的字符（例如代码页850）的代码页上，它们的数量进一步限制为22。
   0 1 2 3 4 5 6 7 8 9 A B C D E F
   B││╣║╝
   C└├├─╩╩╩╩╩╩
   ┘
   注意：非双精度字符是“细”字符（U + 2500，U + 2502），而不是“宽”字符（U + 2501，U + 2503）。
   Unix，CP / M，BBS
   在许多Unix系统和早期拨号公告板系统上，用于绘制框字符的唯一通用标准是VT100备用字符集。转义序列Esc（（0切换小写ASCII字母的代码来绘制此集合，序列Esc（（B切换回：
   0 1 2 3 4 5 6 7 8 9 A B C D E F
   6┐┌└
   7─├├││
   显示所有符号字符的Bash脚本：
   char =（6a 6b 6c 6d 6e 71 74 75 76 77 78）
   对于$ {char [*]}中的i
   做
   printf“ 0x $ i \ x $ i \ e（0 \ x $ i \ e（B \ n”
   做完了
   在某些终端上，这些字符根本不可用，并且转义序列的复杂性阻碍了它们的使用，因此通常仅使用近似于箱形绘图字符的ASCII字符，例如-（hyphen-minus），|。 （竖线），_（下划线），=（等号）和+（加号）以一种ASCII艺术形式出现。
   现代的Unix终端仿真器使用Unicode，因此可以访问上面列出的画线字符。
   历史的
   1970年代和1980年代的许多微型计算机都有自己的专有字符集，其中还包括绘图字符。其中一些集合（例如Commodore的PETSCII）包括没有相应Unicode字符的箱形绘图符号。

ZX81半图形
Sinclair ZX81和Spectrum包括一组带有块元素和抖动模式的文本符号图形。
BBC Micro可以利用图文电视7位字符集，该字符集具有128个方框绘图字符，其代码点与常规的字母数字和标点符号共享。控制字符用于在常规文本和方框图之间切换。
MouseText是Apple IIc，IIe和IIgs的一组显示字符，其中包括框形图字符。
一些最近的嵌入式系统还使用专有字符集，通常是对ISO 8859字符集的扩展，其中包括箱形绘图字符或其他特殊符号。
世界标准图文电视（WST）对某些图形使用像素绘制字符。字符单元划分为2×3的区域，并为“像素”的所有可能组合分配2 = 64个代码位置。但是，这些字符不包含在Unicode标准中。

使用等宽字体由标准箱形图字符制成的示例图：
┌─┬┐╔═╦╗─╥╖
││││││
├─┼┤╠═╬╣─╫╢
╚═─┴┘
──────────────┐
│╔═══╗一些文字│▒
│╚═╦═╝框中的││
╞═╤══牛皮══╤═══════════╡▒
│├──┬──┤│▒
│└──┴──┘│▒
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字体 中文百科 字体在书法和印刷领域是指文本的式样。依照ISO/IEC 9541-1:1991（ISO/IEC 9541 Information technology – Font information interchange；ISO/IEC 9541-1:1991 Architecture）的附录A《字体设计分类》，拉丁字母字体顶级分为下列8大类： 安色尔体类， 石刻类， 黑体字母类， 衬线类， 无衬线类， 手写体类， 装饰类， 符号和装饰类。 在GB/T 169**.1中添加了第九类传统汉字类。 名称与概念 “字形”（glyph）指单个字（字母、汉字、符号等）的形体。意思相同的字也可能用到不同字体（如繁体字）。 所谓“字体”（typeface）与“字体”（font），都是排印学与书法领域的专有名词。无论港澳台、中国大陆还是欧美等国非专业普通人士都无法区分作为专业名词的“字体”（typeface）与“字体”（font）。font是指某套具有同样样式、尺寸的字形，如“12号常规宋体字”；typeface则是一或多个含有共通设计要素的，包括罗马正体和意大利斜体等的font在一或多个尺寸的集合，具有同一种特定的风格。 各个中文使用地区对于typeface和font没有通用的翻译。中国大陆国家标准（GB/T 169**.1-1997，为国际标准的官方翻译）将typeface译为“字体名称”，font译为“字体”。专业人士也将typeface译为“字体”。一般可将typeface译为“字体”，font译为“字体”。 篆书、隶书、楷书、草书、宋体、仿宋体、黑体等分别是某类相似风格（也称“书体”）的许多个字体的集合，而不是一种字体。两位书法家写出来的楷书就可称为两种字体；宋体在计算机上就有中易宋体和新细明体等字体。 20世纪90年代前后，储存于计算机上的字形数据库逐渐约定俗成地被英语用户称为“computer font”，虽然“font”在排印学与书法领域的原意和这里所用的并不是非常吻合。对于“computer font”中的“font”，中国大陆和香港翻译不同，分别为计算机“字体”和电脑“字体”。随着可缩放的矢量电脑字体的出现，“字体”与“字体”之间的界限也逐渐模糊。 衬线 衬线指的是字形笔画末端的装饰细节部分。衬线体看起来会较整齐，有助提高阅读性。无衬线体较接近人手书写的外形。 西文本体 罗马字母 罗马字母即“拉丁字母”，是一套表音文本的书写系统，由多数欧洲语言采用。 大写字母的形成 罗马字母诞生于公元前，最初只有大写字母，由于是碑刻文本，字形的笔画清晰明了。 小写字母的形成 4世纪左右，因为鹅毛笔的普及，伴随着书写，大写字母逐渐变为一种圆润的连笔字母，形成了接近小写字母的安色尔体。之后的9世纪形成了接近于现代小写字母的卡洛林体。 特排字体 在凸版印刷和照相排版的时代，许多最常用的字体都包含一种叫做“特排字体”的变体。设计特排字体，是为了在大尺寸（一般在36pt或更大）下获得最佳的显示效果，通常是用于报纸的大标题或是书籍的封面。 特排字体的主要特征是，没有“油墨陷阱”——在字母笔画接合部的向内的小凹陷。在小字号印刷时，这样的凹陷有助于收纳凸版印刷时候多余的油墨，在保持字体原有外观设计意图的同时，为印刷提供一些回旋余地。这是凸版印刷的局限，油墨的量很难精确的控制，同时纸张的粗糙程度和对油墨的吸收程度不同，多余的油墨就有可能在笔画结合的地方溢出，导致笔画粘连不清，印刷的品质难于控制。因此油墨陷阱在一定程度上可以降低凸版印刷的废品率。 在大字号情况下，油墨陷阱就不是必要的（更重要的是，会影响美观），因此特排字体就没有这样的设计。现今的数字化字体通常都用于平版印刷、电子照排印刷等场合，不会受到凸版印刷供墨不稳定的影响，因而油墨陷阱基本上没有了用武之地。这就是当今数字化排印领域中罕见特排字体的原因，虽然它们在凸版印刷的时代盛行一时。 现今的数字化字体中有时也会提供一个叫做“特排”的变体，则是在风格上有所差异，以改善字体在大字号下的使用效果。 不幸的是，在桌面出版革命20多年之后，现今的排印从业人员中有铅字排版经验的已经很少了，因而把“特排字体”当成“装饰字体”的同义术语而误用的情形也变得普遍。 英语百科 A Specimen, a broadsheet with examples of typefaces and fonts available. Printed by William Caslon, letter founder; from the 1728 Cyclopaedia. In typography, a typeface (also known as font family) is a set of one or more fonts each composed of glyphs that share common design features. Each font of a typeface has a specific weight, style, condensation, width, slant, italicization, ornamentation, and designer or foundry (and formerly size, in metal fonts). For example, “ITC Garamond Bold Condensed Italic” means the bold, condensed-width, italic version of ITC Garamond. It is a different font from “ITC Garamond Condensed Italic” and “ITC Garamond Bold Condensed,” but all are fonts within the same typeface, “ITC Garamond.” ITC Garamond is a different typeface from “Adobe Garamond” or “Monotype Garamond.” (These are all alternative updates or digitisations of the typeface Garamond, originally created in the 16th century.) There are thousands of different typefaces in existence, with new ones being developed constantly. The art and craft of designing typefaces is called type design. Designers of typefaces are called type designers and are often employed by type foundries. In digital typography, type designers are sometimes also called font developers or font designers. Every typeface is a collection of glyphs, each of which represents an individual letter, number, punctuation mark, or other symbol. The same glyph may be used for characters from different scripts, e.g. Roman uppercase A looks the same as Cyrillic uppercase А and Greek uppercase alpha. There are typefaces tailored for special applications, such as map-making or astrology and mathematics. The term typeface is frequently confused with the term font. Before the advent of digital typography and desktop publishing, the two terms had more clearly understood meanings. Terminology In professional typography, the term typeface is not interchangeable with the word font (originally “fount” in British English, and pronounced “font”), because the term font has historically been defined as a given alphabet and its associated characters in a single size. For example, 8-point Caslon Italic was one font, and 10-point Caslon Italic was another. Historically, fonts came in specific sizes determining the size of characters, and in quantities of sorts or number of each letter provided. The design of characters in a font took into account all these factors. As the range of typeface designs increased and requirements of publishers broadened over the centuries, fonts of specific weight (blackness or lightness) and stylistic variants (most commonly regular or roman as distinct to italic, as well as condensed) have led to font families, collections of closely related typeface designs that can include hundreds of styles. A font family is typically a group of related fonts which vary only in weight, orientation, width, etc., but not design. For example, Times is a font family, whereas Times Roman, Times Italic and Times Bold are individual fonts making up the Times family. Font families typically include several fonts, though some, such as Helvetica, may consist of dozens of fonts. The distinction between font and typeface is that a font designates a specific member of a type family such as roman, boldface, or italic type, while typeface designates a consistent visual appearance or style which can be a “family” or related set of fonts. For example, a given typeface such as Arial may include roman, bold, and italic fonts. In the metal type era, a font also meant a specific point size, but with digital scalable outline fonts this distinction is no longer valid, as a single font may be scaled to any size. The first “extended” font families, which included a wide range of widths and weights in the same general style emerged in the early 1900s, starting with ATF’s Cheltenham (1902–1913), with an initial design by Bertram Grosvenor Goodhue, and many additional faces designed by Morris Fuller Benton. Later examples include Futura, Lucida, ITC Officina. Some became superfamilies as a result of revival, such as Linotype Syntax, Linotype Univers; while others have alternate styling designed as compatible replacements of each other, such as Compatil, Generis. PT Serif (above) and PT Sans (below) from the PT font superfamily, showing the similarities in letter structure. Typeface superfamilies began to emerge when foundries began to include typefaces with significant structural differences, but some design relationship, under the same general family name. Arguably the first superfamily was created when Morris Fuller Benton created Clearface Gothic for ATF in 1910, a sans serif companion to the existing (serifed) Clearface. The superfamily label does not include quite different designs given the same family name for what would seem to be purely marketing, rather than design, considerations: Caslon Antique, Futura Black and Futura Display are structurally unrelated to the Caslon and Futura families, respectively, and are generally not considered part of those families by typographers, despite their names. Additional or supplemental glyphs intended to match a main typeface have been in use for centuries. In some formats they have been marketed as separate fonts. In the early 1990s, the Adobe Systems type group introduced the idea of expert set fonts, which had a standardized set of additional glyphs, including small caps, old style figures, and additional superior letters, fractions and ligatures not found in the main fonts for the typeface. Supplemental fonts have also included alternate letters such as swashes, dingbats, and alternate character sets, complementing the regular fonts under the same family. However, with introduction of font formats such as OpenType, those supplemental glyphs were merged into the main fonts, relying on specific software capabilities to access the alternate glyphs. Since Apple’s and Microsoft’s operating systems supported different character sets in the platform related fonts, some foundries used expert fonts in a different way. These fonts included the characters which were missing on either Macintosh or Windows computers, e.g. fractions, ligatures or some accented glyphs. The goal was to deliver the whole character set to the customer regardless of which operating system was used. The size of typefaces and fonts is traditionally measured in points; point has been defined differently at different times, but now the most popular is the Desktop Publishing point of ⁄72 in (0.0139 in or 0.35 mm). When specified in typographic sizes (points, kyus), the height of an em-square, an invisible box which is typically a bit larger than the distance from the tallest ascender to the lowest descender, is scaled to equal the specified size. For example, when setting Helvetica at 12 point, the em square defined in the Helvetica font is scaled to 12 points or ⁄6 in (0.17 in or 4.3 mm). Yet no particular element of 12-point Helvetica need measure exactly 12 points. Frequently measurement in non-typographic units (feet, inches, meters) will be of the cap-height, the height of the capital letters. Font size is also commonly measured in millimeters (mm) and qs (a quarter of a millimeter, kyu in romanized Japanese) and inches. History Israeli typographer Henri Friedlaender examines Hadassah Hebrew typeface sketches. The sequence was shot in his study in Motza Illit (near Jerusalem) in 1978. Type foundries have cast fonts in lead alloys from the 1450s until the present, although wood served as the material for some large fonts called wood type during the 19th century, particularly in the United States. In the 1890s the mechanization of typesetting allowed automated casting of fonts on the fly as lines of type in the size and length needed. This was known as continuous casting, and remained profitable and widespread until its demise in the 1970s. The first machine of this type was the Linotype machine, invented by Ottmar Mergenthaler. During a brief transitional period (c. 1950s – 1990s), photographic technology, known as phototypesetting, utilized tiny high-resolution images of individual glyphs on a film strip (in the form of a film negative, with the letters as clear areas on an opaque black background). A high-intensity light source behind the film strip projected the image of each glyph through an optical system, which focused the desired letter onto the light-sensitive phototypesetting paper at a specific size and position. This photographic typesetting process permitted optical scaling, allowing designers to produce multiple sizes from a single font, although physical constraints on the reproduction system used still required design changes at different sizes; for example, ink traps and spikes to allow for spread of ink encountered in the printing stage. Manually operated photocomposition systems using fonts on filmstrips allowed fine kerning between letters without the physical effort of manual typesetting, and spawned an enlarged type design industry in the 1960s and 1970s. By the mid-1970s, all of the major typeface technologies and all their fonts were in use: letterpress; continuous casting machines; phototypositors; computer-controlled phototypesetters; and the earliest digital typesetters – bulky machines with primitive processors and CRT outputs. From the mid-1980s, as digital typography has grown, users have almost universally adopted the American spelling font, which has come to primarily refer to a computer file containing scalable outline letterforms (digital font), in one of several common formats. Some typefaces, such as Verdana, are designed primarily for use on computer screens. Digital type Comparison between printed (top) and digital (bottom) versions of Perpetua. Digital type became the dominant form of type in the late 1980s and early 1990s. Digital fonts store the image of each character either as a bitmap in a bitmap font, or by mathematical description of lines and curves in an outline font, also called a vector font. Bitmap fonts were more commonly used in the earlier stages of digital type, and are rarely used today. When an outline font is used, a rasterizing routine (in the application software, operating system or printer) renders the character outlines, interpreting the vector instructions to decide which pixels should be black and which ones white. Rasterization is straightforward at high resolutions such as those used by laser printers and in high-end publishing systems. For computer screens, where each individual pixel can mean the difference between legible and illegible characters, some digital fonts use hinting algorithms to make readable bitmaps at small sizes. Digital fonts may also contain data representing the metrics used for composition, including kerning pairs, component creation data for accented characters, glyph substitution rules for Arabic typography and for connecting script faces, and for simple everyday ligatures like fl. Common font formats include TrueType, OpenType and PostScript Type 1, while Metafont is still used by TeX and its variants. Applications using these font formats, including the rasterizers, appear in Microsoft and Apple Computer operating systems, Adobe Systems products and those of several other companies. Digital fonts are created with font editors such as FontForge, RoboFont, Glyphs, Fontlab’s TypeTool, FontLab Studio, Fontographer, or AsiaFont Studio. Typeface anatomy Typographers have developed a comprehensive vocabulary for describing the many aspects of typefaces and typography. Some vocabulary applies only to a subset of all scripts. Serifs, for example, are a purely decorative characteristic of typefaces used for European scripts, whereas the glyphs used in Arabic or East Asian scripts have characteristics (such as stroke width) that may be similar in some respects but cannot reasonably be called serifs and may not be purely decorative. Serifs Sans serif font Serif font Serif font with serifs highlighted in red Typefaces can be divided into two main categories: serif and sans serif. Serifs comprise the small features at the end of strokes within letters. The printing industry refers to typeface without serifs as sans serif (from French sans, meaning without), or as grotesque (or, in German, grotesk). Great variety exists among both serif and sans serif typefaces. Both groups contain faces designed for setting large amounts of body text, and others intended primarily as decorative. The presence or absence of serifs forms is only one of many factors to consider when choosing a typeface. Typefaces with serifs are often considered easier to read in long passages than those without. Studies on the matter are ambiguous, suggesting that most of this effect is due to the greater familiarity of serif typefaces. As a general rule, printed works such as newspapers and books almost always use serif typefaces, at least for the text body. Web sites do not have to specify a font and can simply respect the browser settings of the user. But of those web sites that do specify a font, most use modern sans serif fonts, because it is commonly believed that, in contrast to the case for printed material, sans serif fonts are easier than serif fonts to read on the low-resolution computer screen. Proportion A proportional typeface contains glyphs of varying widths, while a monospaced (non-proportional or fixed-width) typeface uses a single standard width for all glyphs in the font. Many people generally find proportional typefaces nicer-looking and easier to read, and thus they appear more commonly in professionally published printed material. For the same reason, GUI computer applications (such as word processors and web browsers) typically use proportional fonts. However, many proportional fonts contain fixed-width (tabular) figures so that columns of numbers stay aligned. Monospaced typefaces function better for some purposes because their glyphs line up in neat, regular columns. No glyph is given any more weight than another. Most manually operated typewriters use monospaced fonts. So do text-only computer displays and third- and fourth-generation game console graphics processors, which treat the screen as a uniform grid of character cells. Most computer programs which have a text-based interface (terminal emulators, for example) use only monospaced fonts (or add additional spacing to proportional fonts to fit them in monospaced cells) in their configuration. Monospaced fonts are commonly used by computer programmers for displaying and editing source code so that certain characters (for example parentheses used to group arithmetic expressions) are easy to see. Monospaced fonts may also make it easier to perform optical character recognition. ASCII art usually requires a monospaced font for proper viewing, with the exception of Shift JIS art which takes advantage of the proportional characters in the MS PGothic font. In a web page, the , or

HTML tags most commonly specify monospaced fonts. In LaTeX, the verbatim environment or the Teletype font family (e.g., \texttt{…} or {\ttfamily …}) uses monospaced fonts (in TeX, use {\tt …}). Any two lines of text with the same number of characters in each line in a monospaced typeface should display as equal in width, while the same two lines in a proportional typeface may have radically different widths. This occurs because in a proportional font, glyph widths vary, such that wider glyphs (typically those for characters such as W, Q, Z, M, D, O, H, and U) use more space, and narrower glyphs (such as those for the characters i, t, l, and 1) use less space than the average. In the publishing industry, it was once the case that editors read manuscripts in monospaced fonts (typically Courier) for ease of editing and word count estimates, and it was considered discourteous to submit a manuscript in a proportional font. This has become less universal in recent years, such that authors need to check with editors as to their preference, though monospaced fonts are still the norm. Font metrics The word Sphinx, set in Adobe Garamond Pro to illustrate the concepts of baseline, x-height, body size, descent and ascent. Most scripts share the notion of a baseline: an imaginary horizontal line on which characters rest. In some scripts, parts of glyphs lie below the baseline. The descent spans the distance between the baseline and the lowest descending glyph in a typeface, and the part of a glyph that descends below the baseline has the name descender. Conversely, the ascent spans the distance between the baseline and the top of the glyph that reaches farthest from the baseline. The ascent and descent may or may not include distance added by accents or diacritical marks. In the Latin, Greek and Cyrillic (sometimes collectively referred to as LGC) scripts, one can refer to the distance from the baseline to the top of regular lowercase glyphs (mean line) as the x-height, and the part of a glyph rising above the x-height as the ascender. The distance from the baseline to the top of the ascent or a regular uppercase glyphs (cap line) is also known as the cap height. The height of the ascender can have a dramatic effect on the readability and appearance of a font. The ratio between the x-height and the ascent or cap height often serves to characterize typefaces. Typefaces with the same metrics (i.e., with the same glyph dimensions) are said to be “metric-compatible”, that is, they can be substituted for one another in a document without changing the document’s text flow. Several typefaces have been created to be metric-compatible with widely used proprietary typefaces to allow the editing of documents set in such typefaces in digital typesetting environments where these typefaces are not available. For instance, the open-source Liberation fonts and Croscore fonts have been designed as metric-compatible substitutes for widely used Microsoft fonts. Optical sizing During the metal type era, all type was cut in metal and could only be printed at a specific size. It was a natural process to vary a design at different sizes, making it chunkier and clearer to read at smaller sizes. Many digital fonts are offered in a range of styles for different sizes, especially designs sold for professional printing use by companies such as Adobe. The art of designing fonts for a specific size is known as optical sizing. Others will be offered in only one style, but optimised for a specific size. Designs intended to be printed small may feature larger lower-case letters, chunkier stroke weights and thicker serifs, while fonts intended for display may be more slender. Optical sizes are particularly common for serif fonts, since the fine detail of serif fonts can need to be bulked up for smaller sizes. Typefaces may also be designed differently considering the type of paper on which they will be printed. Designs to be printed on absorbent newsprint paper will be more slender as the ink will naturally spread out as it absorbs into the paper, and may feature ink traps: areas left blank into which the ink will soak as it dries. These corrections will not be needed for printing on high-gloss cardboard or display on-screen. Fonts designed for low-resolution displays, meanwhile, may avoid pure circles, fine lines and details a screen cannot render. Hoefler Text uses non-lining or lower-case figures. Typesetting numbers Proportional (upper) and tabular (lower) figures, drawn as lining figures. Most typefaces, especially modern designs, include a complementary set of numbers. This was not always so: in the metal type era, when fonts were often set to highly standardised metrics, fonts might not include numbers, or a font of numbers in an unusual style might be sold without a matching set of letters. Numbers can be typeset in two independent sets of ways: lining and non-lining figures, and proportional and tabular styles, making for four possible combinations. Most modern typefaces set numbers by default as lining figures, which are the height of upper-case letters. Non-lining figures, styled to match lower-case letters, are often common in fonts intended for body text, as they are thought to be less disruptive to the style of running text. They are also called lower-case numbers or text figures for the same reason. The width of numbers can also be proportional, with a character width tightly matching the width of the character, or tabular, where all numbers have the same width. Proportional spacing places the numbers closely together, reducing empty space in a document, and is thought to allow the numbers to blend into the text more effectively. As tabular spacing makes all numbers with the same number of digits the same width, it is used for typesetting documents such as price lists, stock listings and sums in mathematics textbooks, all of which require columns of numbers to line up on top of each other for easier comparison. Tabular spacing is also a common feature of simple printing devices such as cash registers and date-stamps. Fonts intended for professional use in documents such as business reports may also make the bold style numbers take up the same width as the regular, so a total in bold takes up the same width as the sum in regular style. Characters of uniform width are a standard feature of so-called monospaced fonts, used in programming and on typewriters. However, many fonts that are not monospaced use tabular figures. More complex font designs may include two or more combinations with one as the default and others as alternate characters. Of the four possibilities, non-lining tabular figures are particularly rare since there is no common use for them. Style of typefaces Illustration of different font types and the names of specific specimens Because an abundance of typefaces have been created over the centuries, they are commonly categorized according to their appearance. At the highest level (in the context of Latin-script fonts), one can differentiate Roman, Blackletter, and Gaelic types. Roman types are in the most widespread use today, and are sub-classified as serif, sans serif, ornamental, and script types. Historically, the first European fonts were blackletter, followed by Roman serif, then sans serif and then the other types. The use of Gaelic faces was restricted to the Irish language, though these form a unique if minority class. Typefaces may be monospaced regardless of whether they are Roman, Blackletter, or Gaelic. Symbol typefaces are non-alphabetic. The Cyrillic script comes in two varieties, Roman type (called гражданский шрифт graždanskij šrift) and traditional Slavonic type (called славянский шрифт slavjanskij šrift). Roman typefaces Serif typefaces The three traditional styles of serif typefaces used for body text: old-style, transitional and Didone, represented by Garamond, Baskerville and Didot. Serif, or Roman, typefaces are named for the features at the ends of their strokes. Times Roman and Garamond are common examples of serif typefaces. Serif fonts are probably the most used class in printed materials, including most books, newspapers and magazines. Serif fonts are often classified into three subcategories: Old Style, Transitional, and Didone (or Modern), representative examples of which are Garamond, Baskerville, and Bodoni respectively. Old Style typefaces are influenced by early Italian lettering design. Modern fonts often exhibit a bracketed serif and a substantial difference in weight within the strokes. Though some argument exists as to whether Transitional fonts exist as a discrete category among serif fonts, Transitional fonts lie somewhere between Old Style and Modern style typefaces. Transitional fonts exhibit a marked increase in the variation of stroke weight and a more horizontal serif compared to Old Style. Slab serif designs have particularly large serifs, and date to the early nineteenth century. The earliest slab serif font, Antique, later renamed Egyptian, was first shown in 1815 by the English typefounder Vincent Figgins. Roman, italic, and oblique are also terms used to differentiate between upright and two possible slanted forms of a typeface. Italic and oblique fonts are similar (indeed, oblique fonts are often simply called italics) but there is strictly a difference: italic applies to fonts where the letter forms are redesigned, not just slanted. Almost all serif faces have italic forms; some sans-serif faces have oblique designs. (Most faces do not offer both as this is an artistic choice by the font designer about how the slanted form should look.) Sans serif typefaces The sans-serif Helvetica typeface Sans serif (lit. without serif) designs appeared relatively recently in the history of type design. The first, similar to slab serif designs, was shown in 1816 by William Caslon IV. Sans serif fonts are commonly but not exclusively used for display typography such as signage, headings, and other situations demanding legibility above high readability. The text on electronic media offers an exception to print: most web pages and digitized media are laid out in sans serif typefaces because serifs often detract from readability at the low resolution of displays. Many have minimal variation in stroke width, creating the impression of a minimal, simplified design. A well-known and popular sans serif font is Max Miedinger’s Helvetica, popularized for desktop publishing by inclusion with Apple Computer’s LaserWriter laserprinter and having been one of the first readily available digital typefaces. Arial, popularized by Microsoft, is a common Helvetica substitute. Other fonts such as Futura, Gill Sans, Univers and Frutiger have also remained popular over many decades. Script typefaces Coronet, a script typeface. Script typefaces imitate handwriting or calligraphy. They do not lend themselves to quantities of body text, as people find them harder to read than many serif and sans-serif typefaces; they are typically used for logos or invitations. Historically, most lettering on logos, displays, shop frontages did not use fonts but was rather custom-designed by signpainters and engravers, so many emulate the styles of hand-drawn signs from different historical periods. The genre has developed rapidly in recent years due to modern font formats allowing more complex simulations of handwriting. Examples include Coronet (a quite simple design from 1937) and Zapfino (a much more complicated digital design). Mimicry typefaces Simulated Hebrew. Some decorative typefaces, sometimes called simulation typefaces, have been designed that represent the characters of the Roman alphabet but evoke another writing system. This group includes typefaces designed to appear as Arabic, Chinese characters, Cyrillic, Indic scripts, Greek, Hebrew, Kana, or Thai. These are used largely for the purpose of novelty to make something appear foreign, or to make businesses such as restaurants offering foreign food clearly stand out. Blackletter typefaces Blackletter fonts, the earliest typefaces used with the invention of the printing press, resemble the blackletter calligraphy of that time. Many people refer to them as gothic script. Various forms exist including textualis, rotunda, schwabacher, and fraktur. Gaelic typefaces Gaelic fonts were first used for the Irish language in 1571, and were used regularly for Irish until the early 1960s, though they continue to be used in display type and type for signage. Their use was effectively confined to Ireland, though Gaelic typefaces were designed and produced in France, Belgium, and Italy. Gaelic typefaces make use of insular letterforms, and early fonts made use of a variety of abbreviations deriving from the manuscript tradition. Early fonts used for the Anglo-Saxon language, also using insular letterforms, can be classified as Gaelic typefaces, distinct from Roman or Antiqua typefaces. Various forms exist, including manuscript, traditional, and modern styles, chiefly distinguished as having angular or uncial features. Monospaced typefaces Courier, a monospaced slab serif typeface. All the letters occupy spaces the same width. Monospaced fonts are typefaces in which every glyph is the same width (as opposed to variable-width fonts, where the w and m are wider than most letters, and the i is narrower). The first monospaced typefaces were designed for typewriters, which could only move the same distance forward with each letter typed. Their use continued with early computers, which could only display a single font. Although modern computers can display any desired typeface, monospaced fonts are still important for computer programming, terminal emulation, and for laying out tabulated data in plain text documents; they may also be particularly legible at small sizes due to all characters being quite wide. Examples of monospaced typefaces are Courier, Prestige Elite, Fixedsys, and Monaco. Most monospaced fonts are sans-serif or slab-serif as these designs are easiest to read printed small or display on low-resolution screens, though many exceptions exist. Reverse-contrast typefaces Reverse-contrast ‘Italian’ type compared to the bold design Elephant. Both are very bold, but Elephant’s thick lines are the verticals and the Italian’s are the horizontals. A reverse-contrast type is a typeface in which the stress is reversed from the norm: instead of the vertical lines being the same width or thicker than horizontals, which is normal in Latin-alphabet printing, the horizontal lines are the thickest. Reverse-contrast types are rarely used for body text, and are particularly common in display applications such as headings and posters, in which their unusual structure may be particularly eye-catching. First seen in London in 1821, they were particularly common in the mid- to late nineteenth century in American and British printing and have been revived occasionally since then. They effectively become slab serif designs because of the serifs becoming thick, and are often characterised as part of that genre. In recent times, the reverse-contrast effect has been extended to other kinds of typeface, such as sans-serif designs. Effect typefaces Three typefaces designed for headings, offering a clear contrast to body text Some typefaces have a structure that suggests a three-dimensional letter, such as letters carved into stone. An example of this is the genre known as ‘inline’, ‘block’ ‘outline’ or ‘shadowed’ typefaces. This renders the interior of glyphs in the background color, with a thin line around the edges of the glyphs. In some cases, the outline shows the glyph filled in with the foreground color, surrounded a thin outline mirroring the edges separated by a small gap. (This latter style is often used with “college” typefaces.) Colorized block lettering is often seen in carefully rendered graffiti. A “shadow” effect can also be either designed into a typeface or added to an existing typeface. Designed-in shadows can be stylized or connected to the foreground. An after-market shadow effect can be created by making two copies of each glyph, slightly offset in a diagonal direction and possibly in different colors. Drop shadows can also be dynamically created by rendering software. The shadow effect is often combined with the outline effect, where the top layer is shown in white with black outline and the bottom layer in black, for greater contrast. An example typeface with an ‘inline’ effect is Imprint Shadowed, where the shadowed version is more widely distributed than the regular design. Most effect typefaces are categorisable as display types, intended for headings. CJK typefaces CJK, or Chinese, Japanese and Korean typefaces consist of wide ranging sets of glyphs. They include all of the ASCII, European Roman glyphs and Cyrillic glyphs and often Persian, Hebrew and Arabic. Most uniquely, however, their native character set’s glyphs are designed to fit within a square. This is somewhat similar to monospaced type faces, but allows for vertical, horizontal, right-to-left and left-to-right orientation. They also include a set of Extended Latin characters with glyphs and metrics redesigned for the square in addition to the standard variety. This commonly results in complex, often conflicting rules and conventions of mixing languages in type. Mincho With CJK typefaces, Mincho style tends to be something like Serifs for the end of stems, and in fact includes Serifed glyphs for Extended Latin and Cyrillic sets within a typeface. Gothic With CJK typefaces, Goth style tends to be something like Sans Serifs with squarish, cut off end-caps for the end of stems, and in fact includes Sans Serif glyphs for Extended Latin and Cyrillic sets within a typeface. Maru With CJK typefaces, Maru style tends to be something like Sans Serifs with rounded end-caps for the end of stems, and in fact includes Rounded Sans Serif glyphs for Extended Latin and Cyrillic sets within a typeface. Display type London ***********'s Johnston typeface, printed on a large sign. Display type refers to the use of type at large sizes, perhaps 30 points or larger. Some typefaces are considered useful solely at display sizes, and are known as display faces. Most effect typefaces are display types. Common features of display type include tighter default letter spacing, finer details and serifs, slightly more condensed letter shapes and larger differences between thick and thin strokes; many of these are most visible in serif designs. Many display typefaces in the past such as those intended for posters and newspaper headlines were also only cut in capitals, since it was assumed lower-case would not be needed, or at least with no italics. This was true of many early sans-serif fonts. In the days of metal type, when each size was cut individually, display types were often cut that were adjusted for display use. These modifications continued to be made even after fonts started to be made by scaling using a pantograph, but began to fade away with the advent of phototypesetting and then digital fonts, which can both be printed at any size. Premium digital fonts used for magazines, books and newspapers do often include display variants, but they are often not included with typefaces bundled with operating systems and desktop publishing software. Comparison between the typeface Perpetua and its display variant, Perpetua Titling (above). The display type has slimmer stroke width and taller letters. Decades into the desktop publishing revolution, few typographers with metal foundry type experience are still working, and few digital typefaces are optimized specifically for different sizes, so the misuse of the term display typeface as a synonym for ornamental type has become widespread; properly speaking, ornamental typefaces are a subcategory of display typefaces. At the same time, with new printing techniques, typefaces have largely replaced hand-lettering for very large signs and notices that would once have been painted or carved by hand. Small print typefaces Some typefaces are specifically designed to be printed at small sizes, for example in telephone directories or on newsprint paper. Bell Gothic and Bell Centennial, commissioned for telephone directories, are notable examples of this. Small-print designs often feature a large x-height, and a chunky design. Some fonts used at such sizes may be members of a larger family with members lacking such adaptations. For example, the Times New Roman family contains some designs intended for small print use, as do many members of the Adobe Originals library such as Minion. In the metal type era, typefaces intended to be printed small contained ink traps, small indentations at the junctions of strokes that would be filled up with ink spreading out, maintaining the intended appearance of the type design. Without ink traps, the excess ink would blob and ruin the crisp edge. At larger sizes, these ink traps were not necessary, so display faces did not have them. They have also been removed from most digital fonts, as these will normally be viewed on screen or printed through inkjet printing, laser printing, offset lithography, electrophotographic printing or other processes that do not show the ink spread of letterpress. Ink traps have remained common on designs intended to be printed on low-quality, absorbent paper, especially newsprint and telephone directories. A Latin text used in a sample of Caslon. The foreign language concentrates attention on the typeface design rather than the meaning of the text. Texts used to demonstrate typefaces A sentence that uses all of the alphabet (a pangram), such as “The quick brown fox jumps over the lazy dog”, is often used as a design aesthetic tool to demonstrate the personality of a typeface’s characters in a setting (because it displays all the letters of the alphabet). For extended settings of typefaces graphic designers often use nonsense text (commonly referred to as greeking), such as lorem ipsum or Latin text such as the beginning of Cicero’s In Catilinam. Greeking is used in typography to determine a typeface’s colour, or weight and style, and to demonstrate an overall typographic aesthetic prior to actual type setting. Non-character typefaces Specimens of printed floral borders from an 1897 type foundry specimen book. The process of printing typefaces has historically been far simpler than commissioning and engraving custom illustrations, especially as many non-text features of printed works like symbols and borders were likely to be reused by a printer in future. Non-character typefaces have therefore been created for elements of documents that are not letters but are likely to be reused regularly. These include: Ornamental typefaces Ornamental (also known as novelty or sometimes display) typefaces are used to decorate a page. Historically complex interlocking patterns known as arabesques were common in fine printing, as were floral borders known as fleurons evoking hand-drawn manuscripts. In the metal type era, type-founding companies often would offer pre-formed illustrations as fonts showing objects and designs likely to be useful for printing and advertisements, the equivalent of modern clip art and stock photographs. As examples, the American Type Founders specimen of 1897 offered designs including baseball players, animals, Christmas wreaths, designs for cheques, and emblems such as state seals for government printing. The practice has declined as printing custom illustrations and colour printing using processes such as lithography has become cheaper, although illustration typefaces are still sold by some companies. See above for the historical definition of display typeface. Symbol typefaces Examples of dingbats, which could be used in documents such as tourist guides or TV listings. Symbol, or dingbat, typefaces consist of symbols (such as decorative bullets, clock faces, railroad timetable symbols, CD-index, or TV-channel enclosed numbers) rather than normal text characters. Common, widely used symbol typeface releases include Zapf Dingbats and Wingdings, though many may be created internally by a publication for its own use and some typefaces may have a symbol range included. Marlett is an example of a font used by Windows to draw elements of windows and icons. Emoji Emoji are pictograms that can be used and displayed inline with text. They are similar to previous symbol typefaces, but with a much larger range of characters, such as symbols for common objects, animals, food types, weather and emotions. Originally developed in Japan, they are now commonly installed on many computer and smartphone operating systems. Following standardisation and inclusion in the Unicode standard, allowing them to be used internationally, the number of Emoji characters has rapidly increased to meet the demands of an expanded range of cultures using them; unlike many previous symbol typefaces, they are interchangeable with the ability to display the pictures of the same meaning in a range of fonts on different operating systems. The popularity of emoji has meant that characters have sometimes gained culture-specific meanings not inherent to the design. Both colour and monochrome emoji typefaces exist, as well as at least one animated design. Music typefaces Typefaces that include musical notes and other needed symbols have been developed to print sheet music. Intellectual property The metal type Californian by Frederic Goudy with two alternative digital revivals. It can be seen that the second has a more even tone with less contrast in stroke width. Typefaces are born from the struggle between rules and results. Squeezing a square about 1% helps it look more like a square; to appear the same height as a square, a circle must be measurably taller. The two strokes in an X aren’t the same thickness, nor are their parallel edges actually parallel; the vertical stems of a lowercase alphabet are thinner than those of its capitals; the ascender on a d isn’t the same length as the descender on a p, and so on. For the rational mind, type design can be a maddening game of drawing things differently in order to make them appear the same. Jonathan Hoefler & Tobias Frere-Jones In Eltra Corp. v. Ringer, the United States Court of Appeals for the Fourth Circuit held that typeface designs are not subject to copyright. However, in the USA novel and non-obvious typeface designs are subject to protection by design patents. Digital fonts that embody a particular design are often subject to copyright as computer programs. The names of the typefaces can be trademarked. As a result of these various means of legal protection, sometimes the same typeface exists in multiple names and implementations. Some elements of the software engines used to display fonts on computers have or had software patents associated with them. In particular, Apple Inc. patented some of the hinting algorithms for TrueType, requiring open source alternatives such as FreeType to use different algorithms until Apple’s TrueType hinting patents expired in May 2010. Although typeface design is not subject to copyright in the United States under the 1976 Copyright Act, the United States District Court for the Northern District of California in Adobe Systems, Inc. v. Southern Software, Inc. (No. C95-20710 RMW, N.D. Cal. January 30, 1998) found that there was original authorship in the placement of points on a computer font’s outline; i.e., because a given outline can be expressed in myriad ways, a particular selection and placement of points has sufficient originality to qualify for copyright. Some western countries, including the United Kingdom, extend copyright protection to typeface designs. However, this has no impact on protection in the United States, because all of the major copyright treaties and agreements to which the U.S. is a party (such as the Berne Convention, the WIPO Copyright Treaty, and TRIPS) operate under the principle of national treatment, under which a country is obligated to provide no greater or lesser protection to works from other countries than it provides to domestically produced works. 声明：以上百科文字由Wikimedia Foundation基于Creative Commons协议之条款提供。相关文字仅供参考，其表述的内容不代表本站观点。
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HTML tags most commonly specify monospaced fonts. In LaTeX, the verbatim environment or the Teletype font family (e.g., \texttt{…} or {\ttfamily …}) uses monospaced fonts (in TeX, use {\tt …}). Any two lines of text with the same number of characters in each line in a monospaced typeface should display as equal in width, while the same two lines in a proportional typeface may have radically different widths. This occurs because in a proportional font, glyph widths vary, such that wider glyphs (typically those for characters such as W, Q, Z, M, D, O, H, and U) use more space, and narrower glyphs (such as those for the characters i, t, l, and 1) use less space than the average. In the publishing industry, it was once the case that editors read manuscripts in monospaced fonts (typically Courier) for ease of editing and word count estimates, and it was considered discourteous to submit a manuscript in a proportional font. This has become less universal in recent years, such that authors need to check with editors as to their preference, though monospaced fonts are still the norm. Font metrics The word Sphinx, set in Adobe Garamond Pro to illustrate the concepts of baseline, x-height, body size, descent and ascent. Most scripts share the notion of a baseline: an imaginary horizontal line on which characters rest. In some scripts, parts of glyphs lie below the baseline. The descent spans the distance between the baseline and the lowest descending glyph in a typeface, and the part of a glyph that descends below the baseline has the name descender. Conversely, the ascent spans the distance between the baseline and the top of the glyph that reaches farthest from the baseline. The ascent and descent may or may not include distance added by accents or diacritical marks. In the Latin, Greek and Cyrillic (sometimes collectively referred to as LGC) scripts, one can refer to the distance from the baseline to the top of regular lowercase glyphs (mean line) as the x-height, and the part of a glyph rising above the x-height as the ascender. The distance from the baseline to the top of the ascent or a regular uppercase glyphs (cap line) is also known as the cap height. The height of the ascender can have a dramatic effect on the readability and appearance of a font. The ratio between the x-height and the ascent or cap height often serves to characterize typefaces. Typefaces with the same metrics (i.e., with the same glyph dimensions) are said to be “metric-compatible”, that is, they can be substituted for one another in a document without changing the document’s text flow. Several typefaces have been created to be metric-compatible with widely used proprietary typefaces to allow the editing of documents set in such typefaces in digital typesetting environments where these typefaces are not available. For instance, the open-source Liberation fonts and Croscore fonts have been designed as metric-compatible substitutes for widely used Microsoft fonts. Optical sizing During the metal type era, all type was cut in metal and could only be printed at a specific size. It was a natural process to vary a design at different sizes, making it chunkier and clearer to read at smaller sizes. Many digital fonts are offered in a range of styles for different sizes, especially designs sold for professional printing use by companies such as Adobe. The art of designing fonts for a specific size is known as optical sizing. Others will be offered in only one style, but optimised for a specific size. Designs intended to be printed small may feature larger lower-case letters, chunkier stroke weights and thicker serifs, while fonts intended for display may be more slender. Optical sizes are particularly common for serif fonts, since the fine detail of serif fonts can need to be bulked up for smaller sizes. Typefaces may also be designed differently considering the type of paper on which they will be printed. Designs to be printed on absorbent newsprint paper will be more slender as the ink will naturally spread out as it absorbs into the paper, and may feature ink traps: areas left blank into which the ink will soak as it dries. These corrections will not be needed for printing on high-gloss cardboard or display on-screen. Fonts designed for low-resolution displays, meanwhile, may avoid pure circles, fine lines and details a screen cannot render. Hoefler Text uses non-lining or lower-case figures. Typesetting numbers Proportional (upper) and tabular (lower) figures, drawn as lining figures. Most typefaces, especially modern designs, include a complementary set of numbers. This was not always so: in the metal type era, when fonts were often set to highly standardised metrics, fonts might not include numbers, or a font of numbers in an unusual style might be sold without a matching set of letters. Numbers can be typeset in two independent sets of ways: lining and non-lining figures, and proportional and tabular styles, making for four possible combinations. Most modern typefaces set numbers by default as lining figures, which are the height of upper-case letters. Non-lining figures, styled to match lower-case letters, are often common in fonts intended for body text, as they are thought to be less disruptive to the style of running text. They are also called lower-case numbers or text figures for the same reason. The width of numbers can also be proportional, with a character width tightly matching the width of the character, or tabular, where all numbers have the same width. Proportional spacing places the numbers closely together, reducing empty space in a document, and is thought to allow the numbers to blend into the text more effectively. As tabular spacing makes all numbers with the same number of digits the same width, it is used for typesetting documents such as price lists, stock listings and sums in mathematics textbooks, all of which require columns of numbers to line up on top of each other for easier comparison. Tabular spacing is also a common feature of simple printing devices such as cash registers and date-stamps. Fonts intended for professional use in documents such as business reports may also make the bold style numbers take up the same width as the regular, so a total in bold takes up the same width as the sum in regular style. Characters of uniform width are a standard feature of so-called monospaced fonts, used in programming and on typewriters. However, many fonts that are not monospaced use tabular figures. More complex font designs may include two or more combinations with one as the default and others as alternate characters. Of the four possibilities, non-lining tabular figures are particularly rare since there is no common use for them. Style of typefaces Illustration of different font types and the names of specific specimens Because an abundance of typefaces have been created over the centuries, they are commonly categorized according to their appearance. At the highest level (in the context of Latin-script fonts), one can differentiate Roman, Blackletter, and Gaelic types. Roman types are in the most widespread use today, and are sub-classified as serif, sans serif, ornamental, and script types. Historically, the first European fonts were blackletter, followed by Roman serif, then sans serif and then the other types. The use of Gaelic faces was restricted to the Irish language, though these form a unique if minority class. Typefaces may be monospaced regardless of whether they are Roman, Blackletter, or Gaelic. Symbol typefaces are non-alphabetic. The Cyrillic script comes in two varieties, Roman type (called гражданский шрифт graždanskij šrift) and traditional Slavonic type (called славянский шрифт slavjanskij šrift). Roman typefaces Serif typefaces The three traditional styles of serif typefaces used for body text: old-style, transitional and Didone, represented by Garamond, Baskerville and Didot. Serif, or Roman, typefaces are named for the features at the ends of their strokes. Times Roman and Garamond are common examples of serif typefaces. Serif fonts are probably the most used class in printed materials, including most books, newspapers and magazines. Serif fonts are often classified into three subcategories: Old Style, Transitional, and Didone (or Modern), representative examples of which are Garamond, Baskerville, and Bodoni respectively. Old Style typefaces are influenced by early Italian lettering design. Modern fonts often exhibit a bracketed serif and a substantial difference in weight within the strokes. Though some argument exists as to whether Transitional fonts exist as a discrete category among serif fonts, Transitional fonts lie somewhere between Old Style and Modern style typefaces. Transitional fonts exhibit a marked increase in the variation of stroke weight and a more horizontal serif compared to Old Style. Slab serif designs have particularly large serifs, and date to the early nineteenth century. The earliest slab serif font, Antique, later renamed Egyptian, was first shown in 1815 by the English typefounder Vincent Figgins. Roman, italic, and oblique are also terms used to differentiate between upright and two possible slanted forms of a typeface. Italic and oblique fonts are similar (indeed, oblique fonts are often simply called italics) but there is strictly a difference: italic applies to fonts where the letter forms are redesigned, not just slanted. Almost all serif faces have italic forms; some sans-serif faces have oblique designs. (Most faces do not offer both as this is an artistic choice by the font designer about how the slanted form should look.) Sans serif typefaces The sans-serif Helvetica typeface Sans serif (lit. without serif) designs appeared relatively recently in the history of type design. The first, similar to slab serif designs, was shown in 1816 by William Caslon IV. Sans serif fonts are commonly but not exclusively used for display typography such as signage, headings, and other situations demanding legibility above high readability. The text on electronic media offers an exception to print: most web pages and digitized media are laid out in sans serif typefaces because serifs often detract from readability at the low resolution of displays. Many have minimal variation in stroke width, creating the impression of a minimal, simplified design. A well-known and popular sans serif font is Max Miedinger’s Helvetica, popularized for desktop publishing by inclusion with Apple Computer’s LaserWriter laserprinter and having been one of the first readily available digital typefaces. Arial, popularized by Microsoft, is a common Helvetica substitute. Other fonts such as Futura, Gill Sans, Univers and Frutiger have also remained popular over many decades. Script typefaces Coronet, a script typeface. Script typefaces imitate handwriting or calligraphy. They do not lend themselves to quantities of body text, as people find them harder to read than many serif and sans-serif typefaces; they are typically used for logos or invitations. Historically, most lettering on logos, displays, shop frontages did not use fonts but was rather custom-designed by signpainters and engravers, so many emulate the styles of hand-drawn signs from different historical periods. The genre has developed rapidly in recent years due to modern font formats allowing more complex simulations of handwriting. Examples include Coronet (a quite simple design from 1937) and Zapfino (a much more complicated digital design). Mimicry typefaces Simulated Hebrew. Some decorative typefaces, sometimes called simulation typefaces, have been designed that represent the characters of the Roman alphabet but evoke another writing system. This group includes typefaces designed to appear as Arabic, Chinese characters, Cyrillic, Indic scripts, Greek, Hebrew, Kana, or Thai. These are used largely for the purpose of novelty to make something appear foreign, or to make businesses such as restaurants offering foreign food clearly stand out. Blackletter typefaces Blackletter fonts, the earliest typefaces used with the invention of the printing press, resemble the blackletter calligraphy of that time. Many people refer to them as gothic script. Various forms exist including textualis, rotunda, schwabacher, and fraktur. Gaelic typefaces Gaelic fonts were first used for the Irish language in 1571, and were used regularly for Irish until the early 1960s, though they continue to be used in display type and type for signage. Their use was effectively confined to Ireland, though Gaelic typefaces were designed and produced in France, Belgium, and Italy. Gaelic typefaces make use of insular letterforms, and early fonts made use of a variety of abbreviations deriving from the manuscript tradition. Early fonts used for the Anglo-Saxon language, also using insular letterforms, can be classified as Gaelic typefaces, distinct from Roman or Antiqua typefaces. Various forms exist, including manuscript, traditional, and modern styles, chiefly distinguished as having angular or uncial features. Monospaced typefaces Courier, a monospaced slab serif typeface. All the letters occupy spaces the same width. Monospaced fonts are typefaces in which every glyph is the same width (as opposed to variable-width fonts, where the w and m are wider than most letters, and the i is narrower). The first monospaced typefaces were designed for typewriters, which could only move the same distance forward with each letter typed. Their use continued with early computers, which could only display a single font. Although modern computers can display any desired typeface, monospaced fonts are still important for computer programming, terminal emulation, and for laying out tabulated data in plain text documents; they may also be particularly legible at small sizes due to all characters being quite wide. Examples of monospaced typefaces are Courier, Prestige Elite, Fixedsys, and Monaco. Most monospaced fonts are sans-serif or slab-serif as these designs are easiest to read printed small or display on low-resolution screens, though many exceptions exist. Reverse-contrast typefaces Reverse-contrast ‘Italian’ type compared to the bold design Elephant. Both are very bold, but Elephant’s thick lines are the verticals and the Italian’s are the horizontals. A reverse-contrast type is a typeface in which the stress is reversed from the norm: instead of the vertical lines being the same width or thicker than horizontals, which is normal in Latin-alphabet printing, the horizontal lines are the thickest. Reverse-contrast types are rarely used for body text, and are particularly common in display applications such as headings and posters, in which their unusual structure may be particularly eye-catching. First seen in London in 1821, they were particularly common in the mid- to late nineteenth century in American and British printing and have been revived occasionally since then. They effectively become slab serif designs because of the serifs becoming thick, and are often characterised as part of that genre. In recent times, the reverse-contrast effect has been extended to other kinds of typeface, such as sans-serif designs. Effect typefaces Three typefaces designed for headings, offering a clear contrast to body text Some typefaces have a structure that suggests a three-dimensional letter, such as letters carved into stone. An example of this is the genre known as ‘inline’, ‘block’ ‘outline’ or ‘shadowed’ typefaces. This renders the interior of glyphs in the background color, with a thin line around the edges of the glyphs. In some cases, the outline shows the glyph filled in with the foreground color, surrounded a thin outline mirroring the edges separated by a small gap. (This latter style is often used with “college” typefaces.) Colorized block lettering is often seen in carefully rendered graffiti. A “shadow” effect can also be either designed into a typeface or added to an existing typeface. Designed-in shadows can be stylized or connected to the foreground. An after-market shadow effect can be created by making two copies of each glyph, slightly offset in a diagonal direction and possibly in different colors. Drop shadows can also be dynamically created by rendering software. The shadow effect is often combined with the outline effect, where the top layer is shown in white with black outline and the bottom layer in black, for greater contrast. An example typeface with an ‘inline’ effect is Imprint Shadowed, where the shadowed version is more widely distributed than the regular design. Most effect typefaces are categorisable as display types, intended for headings. CJK typefaces CJK, or Chinese, Japanese and Korean typefaces consist of wide ranging sets of glyphs. They include all of the ASCII, European Roman glyphs and Cyrillic glyphs and often Persian, Hebrew and Arabic. Most uniquely, however, their native character set’s glyphs are designed to fit within a square. This is somewhat similar to monospaced type faces, but allows for vertical, horizontal, right-to-left and left-to-right orientation. They also include a set of Extended Latin characters with glyphs and metrics redesigned for the square in addition to the standard variety. This commonly results in complex, often conflicting rules and conventions of mixing languages in type. Mincho With CJK typefaces, Mincho style tends to be something like Serifs for the end of stems, and in fact includes Serifed glyphs for Extended Latin and Cyrillic sets within a typeface. Gothic With CJK typefaces, Goth style tends to be something like Sans Serifs with squarish, cut off end-caps for the end of stems, and in fact includes Sans Serif glyphs for Extended Latin and Cyrillic sets within a typeface. Maru With CJK typefaces, Maru style tends to be something like Sans Serifs with rounded end-caps for the end of stems, and in fact includes Rounded Sans Serif glyphs for Extended Latin and Cyrillic sets within a typeface. Display type London *******’s Johnston typeface, printed on a large sign. Display type refers to the use of type at large sizes, perhaps 30 points or larger. Some typefaces are considered useful solely at display sizes, and are known as display faces. Most effect typefaces are display types. Common features of display type include tighter default letter spacing, finer details and serifs, slightly more condensed letter shapes and larger differences between thick and thin strokes; many of these are most visible in serif designs. Many display typefaces in the past such as those intended for posters and newspaper headlines were also only cut in capitals, since it was assumed lower-case would not be needed, or at least with no italics. This was true of many early sans-serif fonts. In the days of metal type, when each size was cut individually, display types were often cut that were adjusted for display use. These modifications continued to be made even after fonts started to be made by scaling using a pantograph, but began to fade away with the advent of phototypesetting and then digital fonts, which can both be printed at any size. Premium digital fonts used for magazines, books and newspapers do often include display variants, but they are often not included with typefaces bundled with operating systems and desktop publishing software. Comparison between the typeface Perpetua and its display variant, Perpetua Titling (above). The display type has slimmer stroke width and taller letters. Decades into the desktop publishing revolution, few typographers with metal foundry type experience are still working, and few digital typefaces are optimized specifically for different sizes, so the misuse of the term display typeface as a synonym for ornamental type has become widespread; properly speaking, ornamental typefaces are a subcategory of display typefaces. At the same time, with new printing techniques, typefaces have largely replaced hand-lettering for very large signs and notices that would once have been painted or carved by hand. Small print typefaces Some typefaces are specifically designed to be printed at small sizes, for example in telephone directories or on newsprint paper. Bell Gothic and Bell Centennial, commissioned for telephone directories, are notable examples of this. Small-print designs often feature a large x-height, and a chunky design. Some fonts used at such sizes may be members of a larger family with members lacking such adaptations. For example, the Times New Roman family contains some designs intended for small print use, as do many members of the Adobe Originals library such as Minion. In the metal type era, typefaces intended to be printed small contained ink traps, small indentations at the junctions of strokes that would be filled up with ink spreading out, maintaining the intended appearance of the type design. Without ink traps, the excess ink would blob and ruin the crisp edge. At larger sizes, these ink traps were not necessary, so display faces did not have them. They have also been removed from most digital fonts, as these will normally be viewed on screen or printed through inkjet printing, laser printing, offset lithography, electrophotographic printing or other processes that do not show the ink spread of letterpress. Ink traps have remained common on designs intended to be printed on low-quality, absorbent paper, especially newsprint and telephone directories. A Latin text used in a sample of Caslon. The foreign language concentrates attention on the typeface design rather than the meaning of the text. Texts used to demonstrate typefaces A sentence that uses all of the alphabet (a pangram), such as “The quick brown fox jumps over the lazy dog”, is often used as a design aesthetic tool to demonstrate the personality of a typeface’s characters in a setting (because it displays all the letters of the alphabet). For extended settings of typefaces graphic designers often use nonsense text (commonly referred to as greeking), such as lorem ipsum or Latin text such as the beginning of Cicero’s In Catilinam. Greeking is used in typography to determine a typeface’s colour, or weight and style, and to demonstrate an overall typographic aesthetic prior to actual type setting. Non-character typefaces Specimens of printed floral borders from an 1897 type foundry specimen book. The process of printing typefaces has historically been far simpler than commissioning and engraving custom illustrations, especially as many non-text features of printed works like symbols and borders were likely to be reused by a printer in future. Non-character typefaces have therefore been created for elements of documents that are not letters but are likely to be reused regularly. These include: Ornamental typefaces Ornamental (also known as novelty or sometimes display) typefaces are used to decorate a page. Historically complex interlocking patterns known as arabesques were common in fine printing, as were floral borders known as fleurons evoking hand-drawn manuscripts. In the metal type era, type-founding companies often would offer pre-formed illustrations as fonts showing objects and designs likely to be useful for printing and advertisements, the equivalent of modern clip art and stock photographs. As examples, the American Type Founders specimen of 1897 offered designs including baseball players, animals, Christmas wreaths, designs for cheques, and emblems such as state seals for government printing. The practice has declined as printing custom illustrations and colour printing using processes such as lithography has become cheaper, although illustration typefaces are still sold by some companies. See above for the historical definition of display typeface. Symbol typefaces Examples of dingbats, which could be used in documents such as tourist guides or TV listings. Symbol, or dingbat, typefaces consist of symbols (such as decorative bullets, clock faces, railroad timetable symbols, CD-index, or TV-channel enclosed numbers) rather than normal text characters. Common, widely used symbol typeface releases include Zapf Dingbats and Wingdings, though many may be created internally by a publication for its own use and some typefaces may have a symbol range included. Marlett is an example of a font used by Windows to draw elements of windows and icons. Emoji Emoji are pictograms that can be used and displayed inline with text. They are similar to previous symbol typefaces, but with a much larger range of characters, such as symbols for common objects, animals, food types, weather and emotions. Originally developed in Japan, they are now commonly installed on many computer and smartphone operating systems. Following standardisation and inclusion in the Unicode standard, allowing them to be used internationally, the number of Emoji characters has rapidly increased to meet the demands of an expanded range of cultures using them; unlike many previous symbol typefaces, they are interchangeable with the ability to display the pictures of the same meaning in a range of fonts on different operating systems. The popularity of emoji has meant that characters have sometimes gained culture-specific meanings not inherent to the design. Both colour and monochrome emoji typefaces exist, as well as at least one animated design. Music typefaces Typefaces that include musical notes and other needed symbols have been developed to print sheet music. Intellectual property The metal type Californian by Frederic Goudy with two alternative digital revivals. It can be seen that the second has a more even tone with less contrast in stroke width. Typefaces are born from the struggle between rules and results. Squeezing a square about 1% helps it look more like a square; to appear the same height as a square, a circle must be measurably taller. The two strokes in an X aren’t the same thickness, nor are their parallel edges actually parallel; the vertical stems of a lowercase alphabet are thinner than those of its capitals; the ascender on a d isn’t the same length as the descender on a p, and so on. For the rational mind, type design can be a maddening game of drawing things differently in order to make them appear the same. Jonathan Hoefler & Tobias Frere-Jones In Eltra Corp. v. Ringer, the United States Court of Appeals for the Fourth Circuit held that typeface designs are not subject to copyright. However, in the USA novel and non-obvious typeface designs are subject to protection by design patents. Digital fonts that embody a particular design are often subject to copyright as computer programs. The names of the typefaces can be trademarked. As a result of these various means of legal protection, sometimes the same typeface exists in multiple names and implementations. Some elements of the software engines used to display fonts on computers have or had software patents associated with them. In particular, Apple Inc. patented some of the hinting algorithms for TrueType, requiring open source alternatives such as FreeType to use different algorithms until Apple’s TrueType hinting patents expired in May 2010. Although typeface design is not subject to copyright in the United States under the 1976 Copyright Act, the United States District Court for the Northern District of California in Adobe Systems, Inc. v. Southern Software, Inc. (No. C95-20710 RMW, N.D. Cal. January 30, 1998) found that there was original authorship in the placement of points on a computer font’s outline; i.e., because a given outline can be expressed in myriad ways, a particular selection and placement of points has sufficient originality to qualify for copyright. Some western countries, including the United Kingdom, extend copyright protection to typeface designs. However, this has no impact on protection in the United States, because all of the major copyright treaties and agreements to which the U.S. is a party (such as the Berne Convention, the WIPO Copyright Treaty, and TRIPS) operate under the principle of national treatment, under which a country is obligated to provide no greater or lesser protection to works from other countries than it provides to domestically produced works. 声明：以上百科文字由Wikimedia Foundation基于Creative Commons协议之条款提供。相关文字仅供参考，其表述的内容不代表本站观点。" class=“voicelink”>
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参考翻译 [复制]
Font
Chinese Encyclopedia
Typeface refers to the style of text in the field of calligraphy and printing. According to Appendix A “Font Design Classification” of ISO/IEC 9541-1:1991 (ISO/IEC 9541 Information technology – Font information interchange; ISO/IEC 9541-1:1991 Architecture), the top-level Latin alphabet fonts are divided into the following 8 categories :
Ansel body type,
Stone carving,
Bold letters
Serifs,
Sans serif,
Handwriting,
Decoration,
Symbols and decorative categories.
Added the ninth type of traditional Chinese characters in GB/T 169.1.
Name and concept
“Glyph” (glyph) refers to the shape of a single character (letters, Chinese characters, symbols, etc.). Words with the same meaning may also use different fonts (such as traditional characters).
The so-called “typeface” (typeface) and “font” (font) are both proper nouns in the field of typography and calligraphy. Non-professional ordinary people in Hong Kong, Macau, Taiwan, China, Europe and the United States and other countries are unable to distinguish “typeface” (font) as a professional noun. font refers to a set of fonts with the same style and size, such as “No. 12 regular Song typeface”; typeface is one or more fonts with common design elements, including Roman font and Italian italic font in one or more sizes Collections have the same specific style.
There is no universal translation for typeface and font in all Chinese usage regions. The national standard of Mainland China (GB/T 169.1-1997, the official translation of international standards) translates typeface into “font name” and font into “font”. **Professionals also translate typeface as “font”. Generally, typeface can be translated as “font” and font as “font”.
Seal script, official script, regular script, cursive script, Song type, imitation Song type, bold type, etc. are a collection of many fonts of a similar style (also called “book style”), rather than a single font. The regular scripts written by the two calligraphers can be called two types of fonts; the Song type has the Zhongyi Song type and the new detailed Ming type on the computer.
Around the 1990s, the glyph database stored on the computer gradually came to be commonly known as “computer font” by English users, although the original meaning of “font” in the fields of typography and calligraphy did not quite match the one used here. For “font” in “computer font”, the translations in Mainland China and **Hong Kong are different, namely computer “font” and computer “font”. With the advent of scalable vector computer fonts, the boundaries between “fonts” and “fonts” have also gradually blurred.
Serif
Serif refers to the decorative detail at the end of the glyph stroke. The serif body will look neat and help improve readability. The sans serif body is closer to the shape written by hand.
Western style
Roman alphabet
The Roman alphabet, or “Latin alphabet”, is a set of phonetic text writing systems used by most European languages.
Formation of capital letters
The Roman alphabet was born in BC. At first, there were only capital letters. Because of the inscription text, the strokes of the glyphs were clear and clear.
Formation of lower case letters
Around the 4th century, because of the popularity of quill pens, with the writing, capital letters gradually changed into a rounded continuous pen letter, forming an Ansel body that is close to lower case letters. The following 9th century formed a Carolingian body close to modern lowercase letters.
Special font
In the era of letterpress printing and phototypesetting, many of the most commonly used fonts contain a variant called “special font”. Special fonts are designed to obtain the best display effect in large sizes (usually 36pt or larger), and are usually used for newspaper headlines or book covers.
The main feature of the special typeface is that there is no “ink trap”-a small inward depression at the junction of the letter strokes. When printing in small font size, such a depression helps to store excess ink during letterpress printing, and provides some leeway for printing while maintaining the original design intention of the font. This is the limitation of letterpress printing. The amount of ink is difficult to control accurately. At the same time, the roughness of the paper and the degree of absorption of ink are different. Excess ink may overflow at the place where the strokes are combined, resulting in unclear strokes. Quality is difficult to control. Therefore, the ink trap can reduce the rejection rate of letterpress printing to a certain extent.
In the case of large font size, the ink trap is not necessary (more importantly, it will affect the appearance), so there is no such design for special fonts. Today’s digital fonts are usually used in lithographic printing, electronic phototype printing and other occasions, will not be affected by the instability of letterpress printing ink supply, so the ink trap is basically useless. This is the reason why special typefaces are rare in the field of digital typography today, although they are popular in the era of letterpress printing.
Today’s digital fonts sometimes also provide a variant called “special arrangement”, which is different in style to improve the use of the font under the large size.
Unfortunately, more than 20 years after the desktop publishing revolution, few typography practitioners today have experience with typesetting, so it’s also a misuse of “special font” as a synonymous term for “decorative font”. Become common.
English Encyclopedia

A Specimen, a broadsheet with examples of typefaces and fonts available. Printed by William Caslon, letter founder; from the 1728 Cyclopaedia.
In typography, a typeface (also known as font family) is a set of one or more fonts each composed of glyphs that share common design features. Each font of a typeface has a specific weight, style, condensation, width, slant, italicization, ornamentation, and designer or foundry (and formerly size, in metal fonts). For example, “ITC Garamond Bold Condensed Italic” means the bold, condensed-width, italic version of ITC Garamond. It is a different font from “ITC Garamond Condensed Italic” and “ITC Garamond Bold Condensed,” but all are fonts within the same typeface, “ITC Garamond.” ITC Garamond is a different typeface from “Adobe Garamond” or “Monotype Garamond.” (These are all alternative updates or digitisations of the typeface Garamond, originally created in the 16th century.) There are thousands of different typefaces in existence, with new ones being developed constantly.
The art and craft of designing typefaces is called type design. Designers of typefaces are called type designers and are often employed by type foundries. In digital typography, type designers are sometimes also called font developers or font designers.
Every typeface is a collection of glyphs, each of which represents an individual letter, number, punctuation mark, or other symbol. The same glyph may be used for characters from different scripts, eg Roman uppercase A looks the same as Cyrillic uppercase А and Greek uppercase alpha. There are typefaces tailored for special applications, such as map-making or astrology and mathematics.
The term typeface is frequently confused with the term font. Before the advent of digital typography and desktop publishing, the two terms had more clearly understood meanings.
Terminology
In professional typography, the term typeface is not interchangeable with the word font (originally “fount” in British English, and pronounced “font”), because the term font has historically been defined as a given alphabet and its associated characters in a single size . For example, 8-point Caslon Italic was one font, and 10-point Caslon Italic was another. Historically, fonts came in specific sizes determining the size of characters, and in quantities of sorts or number of each letter provided. The design of characters in a font took into account all these factors.
As the range of typeface designs increased and requirements of publishers broadened over the centuries, fonts of specific weight (blackness or lightness) and stylistic variants (most commonly regular or roman as distinct to italic, as well as condensed) have led to font families, collections of closely related typeface designs that can include hundreds of styles. A font family is typically a group of related fonts which vary only in weight, orientation, width, etc., but not design. For example, Times is a font family, whereas Times Roman, Times Italic and Times Bold are individual fonts making up the Times family. Font families typically include several fonts, though some, such as Helvetica, may consist of dozens of fonts.
The distinction between font and typeface is that a font designates a specific member of a type family such as roman, boldface, or italic type, while typeface designates a consistent visual appearance or style which can be a “family” or related set of fonts. For example, a given typeface such as Arial may include roman, bold, and italic fonts. In the metal type era, a font also meant a specific point size, but with digital scalable outline fonts this distinction is no longer valid, as a single font may be scaled to any size.
The first “extended” font families, which included a wide range of widths and weights in the same general style emerged in the early 1900s, starting with ATF’s Cheltenham (1902–1913), with an initial design by Bertram Grosvenor Goodhue, and many additional faces designed by Morris Fuller Benton. Later examples include Futura, Lucida, ITC Officina. Some became superfamilies as a result of revival, such as Linotype Syntax, Linotype Univers; while others have alternate styling designed as compatible replacements of each other, such as Compatil , Generis.

PT Serif (above) and PT Sans (below) from the PT font superfamily, showing the similarities in letter structure.
Typeface superfamilies began to emerge when foundries began to include typefaces with significant structural differences, but some design relationship, under the same general family name. Arguably the first superfamily was created when Morris Fuller Benton created Clearface Gothic for ATF in 1910, a sans serif companion to the existing (serifed) Clearface. The superfamily label does not include quite different designs given the same family name for what would seem to be purely marketing, rather than design, considerations: Caslon Antique, Futura Black and Futura Display are structurally unrelated to the Caslon and Futura families, respectively, and are generally not considered part of those families by typographers, despite their names.
Additional or supplemental glyphs intended to match a main typeface have been in use for centuries. In some formats they have been marketed as separate fonts. In the early 1990s, the Adobe Systems type group introduced the idea of ​​expert set fonts, which had a standardized set of additional glyphs, including small caps, old style figures, and additional superior letters, fractions and ligatures not found in the main fonts for the typeface. Supplemental fonts have also included alternate letters such as swashes, dingbats, and alternate character sets, complementing the regular fonts under the same family. However, with introduction of font formats such as OpenType, those supplemental glyphs were merged into the main fonts, relying on specific software capabilities to access the alternate glyphs.
Since Apple’s and Microsoft’s operating systems supported different character sets in the platform related fonts, some foundries used expert fonts in a different way. These fonts included the characters which were missing on either Macintosh or Windows computers, eg fractions, ligatures or some accented glyphs. The goal was to deliver the whole character set to the customer regardless of which operating system was used.
The size of typefaces and fonts is traditionally measured in points; point has been defined differently at different times, but now the most popular is the Desktop Publishing point of ⁄72 (in 139) or 0.35 mm. When specified in typographic sizes (points , kyus), the height of an em-square, an invisible box which is typically a bit larger than the distance from the tallest ascender to the lowest descender, is scaled to equal the specified size. For example, when setting Helvetica at 12 point , the em square defined in the Helvetica font is scaled to 12 points or ⁄6 in (0.17 in or 4.3 mm). Yet no particular element of 12-point Helvetica need measure exactly 12 points.
Frequently measurement in non-typographic units (feet, inches, meters) will be of the cap-height, the height of the capital letters. Font size is also commonly measured in millimeters (mm) and qs (a quarter of a millimeter, kyu in romanized Japanese) and inches.
History

Israeli typographer Henri Friedlaender examines Hadassah Hebrew typeface sketches. The sequence was shot in his study in Motza Illit (near Jerusalem) in 1978.
Type foundries have cast fonts in lead alloys from the 1450s until the present, although wood served as the material for some large fonts called wood type during the 19th century, particularly in the United States. In the 1890s the mechanization of typesetting allowed automated casting of fonts on the fly as lines of type in the size and length needed. This was known as continuous casting, and remained profitable and widespread until its demise in the 1970s. The first machine of this type was the Linotype machine, invented by Ottmar Mergenthaler.
During a brief transitional period (c. 1950s – 1990s), photographic technology, known as phototypesetting, utilized tiny high-resolution images of individual glyphs on a film strip (in the form of a film negative, with the letters as clear areas on an opaque black background). A high-intensity light source behind the film strip projected the image of each glyph through an optical system, which focused the desired letter onto the light-sensitive phototypesetting paper at a specific size and position. This photographic typesetting process permitted optical scaling, allowing designers to produce multiple sizes from a single font, although physical constraints on the reproduction system used still required design changes at different sizes; for example, ink traps and spikes to allow for spread of ink encountered in the printing stage. Manually operated photocomposition systems using fonts on filmstrips allowed fine kerning between letters without the physical effort of manual typesetting, and spawned an enlarged type design industry in the 1960s and 1970s.
By the mid-1970s, all of the major typeface technologies and all their fonts were in use: letterpress; continuous casting machines; phototypositors; computer-controlled phototypesetters; and the earliest digital typesetters – bulky machines with primitive processors and CRT outputs. From the mid-1980s, as digital typography has grown, users have almost universally adopted the American spelling font, which has come to primarily refer to a computer file containing scalable outline letterforms (digital font), in one of several common formats. Some typefaces, such as Verdana, are designed primarily for use on computer screens.
Digital type

Comparison between printed (top) and digital (bottom) versions of Perpetua.
Digital type became the dominant form of type in the late 1980s and early 1990s. Digital fonts store the image of each character either as a bitmap in a bitmap font, or by mathematical description of lines and curves in an outline font, also called a vector font. Bitmap fonts were more commonly used in the earlier stages of digital type, and are rarely used today.
When an outline font is used, a rasterizing routine (in the application software, operating system or printer) renders the character outlines, interpreting the vector instructions to decide which pixels should be black and which ones white. Rasterization is straightforward at high resolutions such as those used by laser printers and in high-end publishing systems. For computer screens, where each individual pixel can mean the difference between legible and illegible characters, some digital fonts use hinting algorithms to make readable bitmaps at small sizes.
Digital fonts may also contain data representing the metrics used for composition, including kerning pairs, component creation data for accented characters, glyph substitution rules for Arabic typography and for connecting script faces, and for simple everyday ligatures like fl. Common font formats include TrueType, OpenType and PostScript Type 1, while Metafont is still used by TeX and its variants. Applications using these font formats, including the rasterizers, appear in Microsoft and Apple Computer operating systems, Adobe Systems products and those of several other companies. Digital fonts are created with font editors such as FontForge, RoboFont, Glyphs, Fontlab’s TypeTool, FontLab Studio, Fontographer, or AsiaFont Studio.
Typeface anatomy
Typographers have developed a comprehensive vocabulary for describing the many aspects of typefaces and typography. Some vocabulary applies only to a subset of all scripts. Serifs, for example, are a purely decorative characteristic of typefaces used for European scripts, whereas the glyphs used in Arabic or East Asian scripts have characteristics (such as stroke width) that may be similar in some respects but cannot reasonably be called serifs and may not be purely decorative.
Serifs
Sans serif font
Serif font
Serif font with serifs
highlighted in red
Typefaces can be divided into two main categories: serif and sans serif. Serifs includes the small features at the end of strokes within letters. The printing industry refers to typeface without serifs as sans serif (from French sans, meaning without), or as grotesque (or, in German, grotesk).
Great variety exists among both serif and sans serif typefaces. Both groups contain faces designed for setting large amounts of body text, and others intended primarily as decorative. The presence or absence of serifs forms is only one of many factors to consider when choosing a typeface .
Typefaces with serifs are often considered easier to read in long passages than those without. Studies on the matter are ambiguous, suggesting that most of this effect is due to the greater familiarity of serif typefaces. As a general rule, printed works such as newspapers and books almost always use serif typefaces, at least for the text body. Web sites do not have to specify a font and can simply respect the browser settings of the user. But of those web sites that do specify a font, most use modern sans serif fonts, because it is commonly believed that, in contrast to the case for printed material, sans serif fonts are easier than serif fonts to read on the low-resolution computer screen.
Proportion

A proportional typeface contains glyphs of varying widths, while a monospaced (non-proportional or fixed-width) typeface uses a single standard width for all glyphs in the font.
Many people generally find proportional typefaces nicer-looking and easier to read, and thus they appear more commonly in professionally published printed material. For the same reason, GUI computer applications (such as word processors and web browsers) typically use proportional fonts. However, many proportional fonts contain fixed-width (tabular) figures so that columns of numbers stay aligned.
Monospaced typefaces function better for some purposes because their glyphs line up in neat, regular columns. No glyph is given any more weight than another. Most manually operated typewriters use monospaced fonts. So do text-only computer displays and third- and fourth-generation game console graphics processors, which treat the screen as a uniform grid of character cells. Most computer programs which have a text-based interface (terminal emulators, for example) use only monospaced fonts (or add additional spacing to proportional fonts to fit them in monospaced cells) in their configuration. Monospaced fonts are commonly used by computer programmers for displaying and editing source code so that certain characters (for example parentheses used to group arithmetic expressions) are easy to see. Monospaced fonts may also make it easier to perform optical character recognition.
ASCII art usually requires a monospaced font for proper viewing, with the exception of Shift JIS art which takes advantage of the proportional characters in the MS PGothic font. In a web page, the , or

HTML tags most commonly specify monospaced fonts. In LaTeX, the verbatim environment or the Teletype font family (eg, \texttt{…} or {\ttfamily …}) uses monospaced fonts (in TeX, use {\tt …}).
Any two lines of text with the same number of characters in each line in a monospaced typeface should display as equal in width, while the same two lines in a proportional typeface may have radically different widths. This occurs because in a proportional font, glyph widths vary, such that wider glyphs (typically those for characters such as W, Q, Z, M, D, O, H, and U) use more space, and narrower glyphs (such as those for the characters i, t, l, and 1) use less space than the average.
In the publishing industry, it was once the case that editors read manuscripts in monospaced fonts (typically Courier) for ease of editing and word count estimates, and it was considered discourteous to submit a manuscript in a proportional font. This has become less universal in recent years, such that authors need to check with editors as to their preference, though monospaced fonts are still the norm.
Font metrics

The word Sphinx, set in Adobe Garamond Pro to illustrate the concepts of baseline, x-height, body size, descent and ascent.
Most scripts share the notion of a baseline: an imaginary horizontal line on which characters rest. In some scripts, parts of glyphs lie below the baseline. The descent spans the distance between the baseline and the lowest descending glyph in a typeface, and the part of a glyph that descends below the baseline has the name descender. Conversely, the ascent spans the distance between the baseline and the top of the glyph that reaches farthest from the baseline. The ascent and descent may or may not include distance added by accents or diacritical marks.
In the Latin, Greek and Cyrillic (sometimes collectively referred to as LGC) scripts, one can refer to the distance from the baseline to the top of regular lowercase glyphs (mean line) as the x-height, and the part of a glyph rising above the x-height as the ascender. The distance from the baseline to the top of the ascent or a regular uppercase glyphs (cap line) is also known as the cap height. The height of the ascender can have a dramatic effect on the readability and appearance of a font. The ratio between the x-height and the ascent or cap height often serves to characterize typefaces.
Typefaces with the same metrics (ie, with the same glyph dimensions) are said to be “metric-compatible”, that is, they can be substituted for one another in a document without changing the document’s text flow. Several typefaces have been created to be metric-compatible with widely used proprietary typefaces to allow the editing of documents set in such typefaces in digital typesetting environments where these typefaces are not available. For instance, the open-source Liberation fonts and Croscore fonts have been designed as metric-compatible substitutes for widely used Microsoft fonts.
Optical sizing
During the metal type era, all type was cut in metal and could only be printed at a specific size. It was a natural process to vary a design at different sizes, making it chunkier and clearer to read at smaller sizes. Many digital fonts are offered in a range of styles for different sizes, especially designs sold for professional printing use by companies such as Adobe. The art of designing fonts for a specific size is known as optical sizing. Others will be offered in only one style, but optimised for a specific size. Designs intended to be printed small may feature larger lower-case letters, chunkier stroke weights and thicker serifs, while fonts intended for display may be more slender. Optical sizes are particularly common for serif fonts, since the fine detail of serif fonts can need to be bulked up for smaller sizes.
Typefaces may also be designed differently considering the type of paper on which they will be printed. Designs to be printed on absorbent newsprint paper will be more slender as the ink will naturally spread out as it absorbs into the paper, and may feature ink traps: areas left blank into which the ink will soak as it dries. These corrections will not be needed for printing on high-gloss cardboard or display on-screen. Fonts designed for low-resolution displays, meanwhile, may avoid pure circles, fine lines and details a screen cannot render.

Hoefler Text uses non-lining or lower-case figures.
Typesetting numbers

Proportional (upper) and tabular (lower) figures, drawn as lining figures.
Most typefaces, especially modern designs, include a complementary set of numbers. This was not always so: in the metal type era, when fonts were often set to highly standardised metrics, fonts might not include numbers, or a font of numbers in an unusual style might be sold without a matching set of letters.
Numbers can be typeset in two independent sets of ways: lining and non-lining figures, and proportional and tabular styles, making for four possible combinations.
Most modern typefaces set numbers by default as lining figures, which are the height of upper-case letters. Non-lining figures, styled to match lower-case letters, are often common in fonts intended for body text, as they are thought to be less disruptive to the style of running text. They are also called lower-case numbers or text figures for the same reason.
The width of numbers can also be proportional, with a character width tightly matching the width of the character, or tabular, where all numbers have the same width. Proportional spacing places the numbers closely together, reducing empty space in a document, and is thought to allow the numbers to blend into the text more effectively. As tabular spacing makes all numbers with the same number of digits the same width, it is used for typesetting documents such as price lists, stock listings and sums in mathematics textbooks, all of which require columns of numbers to line up on top of each other for easier comparison. Tabular spacing is also a common feature of simple printing devices such as cash registers and date-stamps. Fonts intended for professional use in documents such as business reports may also make the bold style numbers take up the same width as the regular, so a total in bold takes up the same width as the sum in regular style.
Characters of uniform width are a standard feature of so-called monospaced fonts, used in programming and on typewriters. However, many fonts that are not monospaced use tabular figures. More complex font designs may include two or more combinations with one as the default and others as alternate characters. Of the four possibilities, non-lining tabular figures are particularly rare since there is no common use for them.
Style of typefaces

Illustration of different font types and the names of specific specimens
Because an abundance of typefaces have been created over the centuries, they are commonly categorized according to their appearance. At the highest level (in the context of Latin-script fonts), one can differentiate Roman, Blackletter, and Gaelic types. Roman types are in the most widespread use today, and are sub-classified as serif, sans serif, ornamental, and script types. Historically, the first European fonts were blackletter, followed by Roman serif, then sans serif and then the other types. The use of Gaelic faces was restricted to the Irish language, though these form a unique if minority class. Typefaces may be monospaced regardless of whether they are Roman, Blackletter, or Gaelic. Symbol typefaces are non-alphabetic. The Cyrillic script comes in two varieties, Roman type (called гражданский шрифт graždanskij šrift) and traditional Slavonic type (called славянский шрифт slavjanskij šrift).
Roman typefaces
Serif typefaces

The three traditional styles of serif typefaces used for body text: old-style, transitional and Didone, represented by Garamond, Baskerville and Didot.
Serif, or Roman, typefaces are named for the features at the ends of their strokes. Times Roman and Garamond are common examples of serif typefaces. Serif fonts are probably the most used class in printed materials, including most books, newspapers and magazines. Serif fonts are often classified into three subcategories: Old Style, Transitional, and Didone (or Modern), representative examples of which are Garamond, Baskerville, and Bodoni respectively.
Old Style typefaces are influenced by early Italian lettering design. Modern fonts often exhibit a bracketed serif and a substantial difference in weight within the strokes. Though some argument exists as to whether Transitional fonts exist as a discrete category among serif fonts, Transitional fonts lie somewhere between Old Style and Modern style typefaces. Transitional fonts exhibit a marked increase in the variation of stroke weight and a more horizontal serif compared to Old Style. Slab serif designs have particularly large serifs, and date to the early nineteenth century. The earliest slab serif font, Antique, later renamed Egyptian, was first shown in 1815 by the English typefounder Vincent Figgins.
Roman, italic, and oblique are also terms used to differentiate between upright and two possible slanted forms of a typeface. Italic and oblique fonts are similar (indeed, oblique fonts are often simply called italics) but there is strictly a difference: italic applies to fonts where the letter forms are redesigned, not just slanted. Almost all serif faces have italic forms; some sans-serif faces have oblique designs. (Most faces do not offer both as this is an artistic choice by the font designer about how the slanted form should look.)
Sans serif typefaces

The sans-serif Helvetica typeface
Sans serif (lit. without serif) designs appeared relatively recently in the history of type design. The first, similar to slab serif designs, was shown in 1816 by William Caslon IV. Sans serif fonts are commonly but not exclusively used for display typography such as signage, headings, and other situations demanding legibility above high readability. The text on electronic media offers an exception to print: most web pages and digitized media are laid out in sans serif typefaces because serifs often detract from readability at the low resolution of displays . Many have minimal variation in stroke width, creating the impression of a minimal, simplified design.
A well-known and popular sans serif font is Max Miedinger’s Helvetica, popularized for desktop publishing by inclusion with Apple Computer’s LaserWriter laserprinter and having been one of the first readily available digital typefaces. Arial, popularized by Microsoft, is a common Helvetica substitute. Other fonts such as Futura, Gill Sans, Univers and Frutiger have also remained popular over many decades.
Script typefaces

Coronet, a script typeface.
Script typefaces imitate handwriting or calligraphy. They do not lend themselves to quantities of body text, as people find them harder to read than many serif and sans-serif typefaces; they are typically used for logos or invitations. Historically, most lettering on logos,

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