Microtypography is the name given to a range of methods for improving the readability

Readability

Readability is the ease in which text can be read and understood. Various factors to measure readability have been used, such as "speed of perception," "perceptibility at a distance," "perceptibility in peripheral vision," "visibility," "the reflex blink technique," "rate of work" , "eye...

 and appearance of text, especially justified

Justification (typesetting)

In typesetting, justification is the typographic alignment setting of text or images within a column or "measure" to align along both the left and right margin...

 text. The methods reduce the appearance of large interword spaces and create edges to the text that appear more even.

Methods

There are several methods that can be used.

• The tracking
  Tracking (typography)
  In typography, letter-spacing, also called tracking, refers to the amount of space between a group of letters to affect density in a line or block of text....
  
   (interletter, as opposed to interword, space) can be increased or decreased.
• The width of 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 can be increased or decreased.

  These methods are sometimes called expansion. suggests about 3% expansion or contraction of intercharacter spacing and about 2% expansion or compression of glyphs.

  Compare Kashida

  Kashida

  Kashida is a type of justification used in some cursive scripts, particularly Arabic. In contrast to white-space justification, which increases the length of a line of text by expanding spaces between words or individual letters, kashida justification is accomplished by elongating characters at...

  
   in Persian typography.

• 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 at the end of a line can be extended beyond the end of the line to create a more even line at the edge of the text. This is called protrusion, margin kerning, or hanging punctuation
  Hanging punctuation
  Hanging punctuation or exdentation is a way of typesetting punctuation marks and bullet points, most commonly quotation marks and hyphens, so that they do not disrupt the ‘flow’ of a body of text or ‘break’ the margin of alignment. It is so called because the punctuation appears to ‘hang’ in the...
  
  .
• Multiple different versions of the same glyph with different widths may be used. This method was used by Gutenberg in the 42-line bible (see ), but is less easy now because few fonts come with multiple versions of the same glyph. It is not practical with narrow variants of a font or with different weights of a font because the glyphs look too different from each other to create good effect. It is possible with some multiple master fonts.
• The interline space can be adjusted in a similar way to the interword space to create text blocks of identical height or to avoid widows and orphans.

The following methods are not usually considered part of microtypography, but are important to it.

• Justification
  Justification (typesetting)
  In typesetting, justification is the typographic alignment setting of text or images within a column or "measure" to align along both the left and right margin...
  
   of text. If the text is not justified, the word spacing is fixed and so only the protrusion elements of microtypography are likely to be useful.
• A hyphen
  Hyphen
  The hyphen is a punctuation mark used to join words and to separate syllables of a single word. The use of hyphens is called hyphenation. The hyphen should not be confused with dashes , which are longer and have different uses, or with the minus sign which is also longer...
  
  ation method that can break words at an appropriate point if necessary.
• Kerning
  Kerning
  In typography, kerning is the process of adjusting the spacing between characters in a proportional font, usually to achieve a visually pleasing result. Kerning is the adjustment of the space between individual letter forms vs. tracking which is the uniform adjustment of spacing applied over a...
  
   helps ensure that the space between letters is appropriate before microtypography is applied.

Availability

Adobe

Adobe Systems

Adobe Systems Incorporated is an American computer software company founded in 1982 and headquartered in San Jose, California, United States...

 InDesign provides microtypography and was based on the Hz program

Hz-program

Hz-program was a typographic composition computer program, created by German typeface designer Hermann Zapf. The goal of this program was "to produce the perfect grey type area without the rivers and holes of too-wide word spacing."- History :...

 developed by Hermann Zapf

Hermann Zapf

Hermann Zapf is a German typeface designer who lives in Darmstadt, Germany. He is married to calligrapher and typeface designer Gudrun Zapf von Hesse....

 and Peter Karow. , InDesign is available for Apple Mac OS X and Microsoft Windows operating systems.

The pdfTeX

PdfTeX

The computer program pdfTeX is an extension of Knuth's typesetting program TeX, and was originally written and developed into a publicly usable product by Hàn Thế Thành as a part of the work for his PhD thesis at the Faculty of Informatics, Masaryk University, Brno...

 extension of TeX

TeX

TeX is a typesetting system designed and mostly written by Donald Knuth and released in 1978. Within the typesetting system, its name is formatted as ....

, developed by Hàn Thế Thành incorporates microtypography. It is available for most operating systems. For LaTeX

LaTeX

LaTeX is a document markup language and document preparation system for the TeX typesetting program. Within the typesetting system, its name is styled as . The term LaTeX refers only to the language in which documents are written, not to the editor used to write those documents. In order to...

, the microtype package provides an interface to these microtypographic extensions. , pdfTeX is not compatible with XeTeX

XeTeX

XeTeX is a TeX typesetting engine using Unicode and supporting modern font technologies such as OpenType or Apple Advanced Typography...

, an extension of TeX that makes it easier to use many typographic features of OpenType

OpenType

OpenType is a format for scalable computer fonts. It was built on its predecessor TrueType, retaining TrueType's basic structure and adding many intricate data structures for prescribing typographic behavior...

 fonts. However, in 2010, support for protrusion was added to XeTeX.

ConTeXt

ConTeXt

ConTeXt is a general-purpose document processor. It is especially suited for structured documents, automated document production, very fine typography, and multi-lingual typesetting. It is based in part on the TeX typesetting system, and uses a document markup language for manuscript preparation...

, another typesetting system based on TeX

TeX

TeX is a typesetting system designed and mostly written by Donald Knuth and released in 1978. Within the typesetting system, its name is formatted as ....

, offers both microtypographical features such as expansion and protrusion (a.k.a. hanging punctuation) and OpenType

OpenType

OpenType is a format for scalable computer fonts. It was built on its predecessor TrueType, retaining TrueType's basic structure and adding many intricate data structures for prescribing typographic behavior...

 support through LuaTeX

LuaTeX

LuaTeX is a TeX based computer typesetting system which started as a version of pdfTeX with a Lua scripting engine embedded. After some experiments it was adopted by the pdfTeX team as a successor to pdfTeX . Later in the project some functionality of Aleph was included...

, which is an extended version of pdfTeX

PdfTeX

The computer program pdfTeX is an extension of Knuth's typesetting program TeX, and was originally written and developed into a publicly usable product by Hàn Thế Thành as a part of the work for his PhD thesis at the Faculty of Informatics, Masaryk University, Brno...

.

The wordprocessing

Word processor

A word processor is a computer application used for the production of any sort of printable material....

 packages 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...

 Writer and Microsoft Office Word do not, , support microtypography. They allow pair kerning

Kerning

In typography, kerning is the process of adjusting the spacing between characters in a proportional font, usually to achieve a visually pleasing result. Kerning is the adjustment of the space between individual letter forms vs. tracking which is the uniform adjustment of spacing applied over a...

 and have limited support for ligaturing but automatic ligaturing is not available.

Robin Williams suggests methods for achieving protrusion with wordprocessors and desktop publishing

Desktop publishing

Desktop publishing is the creation of documents using page layout software on a personal computer.The term has been used for publishing at all levels, from small-circulation documents such as local newsletters to books, magazines and newspapers...

packages that do not make it directly available.