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<head>
<title>UK TeX FAQ -- question label adobetypen</title>
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<h3>Adobe font formats</h3>
<!-- type1 type3 -->
<p>Adobe has specified a number of formats for files to represent fonts
in PostScript files; this question doesn’t attempt to be encyclopaedic, but
we’ll discuss the two formats most commonly encountered in the
(La)TeX context, types 1 and 3.
<p>Adobe Type 1 format specifies a means to represent outlines of the glyphs
in a font. The ‘language’ used is closely restricted, to ensure that
the font is rendered as quickly as possible. (Or rather, as quickly
as possible with Adobe’s technology at the time the specification was
written: the structure could well be different if it were specified
now.) The format has long been the basis of the digital type-foundry
business, though things are showing signs of change.
<p>
<p>In the (La)TeX context, Type 1 fonts are extremely important. Apart
from their simple
availability (there are thousands of commercial Type 1 text fonts around), the
commonest reader for PDF files has long (in effect) <em>insisted</em> on
their use (see <a href="FAQ-dvips-pdf.html">PDF quality</a>).
<p>Type 3 fonts have a more forgiving specification. A wide range of
PostScript operators is permissible, including bitmaps operators. Type 3
is therefore the natural format to be used for programs such as
<i>dvips</i> when they auto-generate something to represent
Metafont-generated fonts in a PostScript file. It’s Adobe Acrobat Viewer’s
treatment of bitmap Type 3 fonts that has made direct Metafont output
inreasingly unattractive, in recent years. If you have a PDF
document in which the text looks fuzzy and uneven in Acrobat Reader,
ask Reader for the <code>File</code>->
<code>Document Properties</code>->
<code>Fonts ...</code>, and it will show some font or other as “Type 3”
(usually with encoding “Custom”). (This problem has disappeared
with version 6 of Acrobat Reader.)
<p>Type 3 fonts should not entirely be dismissed, however. Acrobat
Reader’s failure with them is entirely derived from its failure to use
the anti-aliasing techniques common in TeX-ware. Choose a
different set of PostScript graphical operators, and you can make pleasing
Type 3 fonts that don’t “annoy” Reader. For example, you may not
change colour within a Type 1 font glyph, but there’s no such
restriction on a Type 3 font, which opens opportunities for some
startling effects.
<p><p>This question on the Web: <a href="http://www.tex.ac.uk/cgi-bin/texfaq2html?label=adobetypen">http://www.tex.ac.uk/cgi-bin/texfaq2html?label=adobetypen</a>
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