Font substitution
Encyclopedia
Font substitution is the process of using one font
Computer font
A computer font is an electronic data file containing a set of glyphs, characters, or symbols such as dingbats. Although the term font first referred to a set of metal type sorts in one style and size, since the 1990s it is generally used to refer to a scalable set of digital shapes that may be...

 in place of another when the intended font either is not available or does not contain glyph
Glyph
A glyph is an element of writing: an individual mark on a written medium that contributes to the meaning of what is written. A glyph is made up of one or more graphemes....

s for the required characters.

Font substitution can be aided by:
  • classifying fonts into generic font families, such that for example a sans serif font is substituted by another sans serif font.
  • font substitutions defined in operating system's font configuration for concrete font names (font families), such that for example Arial
    Arial
    Arial, sometimes marketed or displayed in software as Arial MT, is a sans-serif typeface and set of computer fonts. Fonts from the Arial family are packaged with Microsoft Windows, some other Microsoft software applications, Apple Mac OS X and many PostScript 3 computer printers...

     font is substituted by metric-compatible font Liberation Sans or Nimbus Sans L.
  • font substitutions defined in application software's (e.g. text processor) font configuration for concrete font names.


When font substitution is being used to find a replacement for an unavailable character, it can lead to inconsistent visual appearance as part of a word or sentence is displayed in one font and another part is displayed in the substituted font. A method to work around this problem is to display the entire word or paragraph in the substituted font. Nevertheless, font substitution may be critical to scripts not well supported by a large font inventory having the required Unicode range.

Examples of systems that perform font substitution include fontconfig
Fontconfig
Fontconfig is a computer program library designed to provide system-wide font configuration, customization, and application access. Fontconfig is written and was originally maintained by Keith Packard...

, Adobe Reader, Unidrv
Unidrv
UniDrv is a GDI-based Microsoft Windows universal printer driver and architecture for non-PostScript printers. It is used to simplify driver development of non-PostScript printers for printer manufacturers...

, Microsoft Word
Microsoft Word
Microsoft Word is a word processor designed by Microsoft. It was first released in 1983 under the name Multi-Tool Word for Xenix systems. Subsequent versions were later written for several other platforms including IBM PCs running DOS , the Apple Macintosh , the AT&T Unix PC , Atari ST , SCO UNIX,...

 (since Word 2002) or OpenOffice.org
OpenOffice.org
OpenOffice.org, commonly known as OOo or OpenOffice, is an open-source application suite whose main components are for word processing, spreadsheets, presentations, graphics, and databases. OpenOffice is available for a number of different computer operating systems, is distributed as free software...

. Not all systems that claim to offer font substitution are able to substitute for missing characters; some are only capable of substituting for missing fonts.

Major modern web browser
Web browser
A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier and may be a web page, image, video, or other piece of content...

s, are capable of font substitution (with the exception of versions of Internet Explorer
Internet Explorer
Windows Internet Explorer is a series of graphical web browsers developed by Microsoft and included as part of the Microsoft Windows line of operating systems, starting in 1995. It was first released as part of the add-on package Plus! for Windows 95 that year...

 older than version 7
Internet Explorer 7
Windows Internet Explorer 7 is a web browser released by Microsoft in October 2006. Internet Explorer 7 is part of a long line of versions of Internet Explorer and was the first major update to the browser in more than 5 years...

).

External links

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