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  Frequently Asked Questions About Fonts

  ----------------------------------------------------------------------

  Compiled by Norman Walsh

  Copyright (C) 1992, 93 by Norman Walsh .

Subject: Table of Contents

  1. General Information

    1.1. Font Houses

    1.2. What's the difference between all these font formats?

    1.3. What about "Multiple Master" fonts?

    1.4. Is there a methodology to describe and classify typefaces?

    1.5. What is the "f" shaped "s" called?

    1.6. What about "Colonial" Typefaces?

    1.7. Where can I get ... fonts.

    1.8. Where can I get fonts for non-Roman alphabets?

    1.10. How can I convert my ... font to ... format?

Subject: 1. General Information

  Many FAQs, including this one, are available by anonymous ftp from

  rtfm.mit.edu in the directory pub/usenet/news.answers.  Each posted

  section of the FAQ is archived under the name that appears in the

  "Archive-name" header at the top of the article.

  This FAQ is a work in progress.  If you have any suggestions, I would be

  delighted to hear them.

  This FAQ is maintained in TeXinfo format.  A Perl script constructs the

  postable FAQ from the TeXinfo sources.  TeX DVI, PostScript, and Info

  versions of this FAQ are available from ftp.shsu.edu in

  /tex-archive/help/comp-fonts-FAQ.  A "Gopher" server is also maintained

  at shsu.edu which can provide interactive access to the FAQ.  Finally,

  an online, hypertext version of the FAQ is maintained (experimentally)

  on jasper.ora.com where an HTTP server runs.  For example, point

  XMosaic (or a similar WWW browser) to http://jasper.ora.com/.

  The posted version of the FAQ is organized in a quasi-digest format so

  that it is easy to find the questions you are interested in.  All

  questions that appear in the table of contents can be found by searching

  for the word "Subject:" followed by the question number.

  The "TeXinfo" distribution from the Free Software Foundation contains a

  program called "Info" that can be used to read the Info version of the

  FAQ in a hypertext manner.  The "TeXinfo" distribution can be obtained

  from prep.ai.mit.edu in the /pub/gnu directory.  At the time of this

  writing, texinfo-2.16.tar.gz is the most recent version.  Info files

  can also be read in hypertext form by GNU Emacs.

  Future versions of the FAQ will make more use of the hypertext

  capabilities provided by the Info format.  At present, the FAQ is

  organized as a simple tree.  A plain ASCII, postable version of the FAQ

  will always be maintained.

  All trademarks used in this document are the trademarks of their

  respective owners.

  Standard disclaimers apply.

Subject: 1.1. Font Houses

  This section will be expanded on in the future.  It contains notes about

  various commercial font houses.

  Compugraphic

  ============

  See "Miles, Agfa Division"

  Miles, Agfa Division

  ====================

  Compugraphic which was for a while the Compugraphic division of Agfa,

  is now calling itself "Miles, Agfa Division" (yes, the Miles drug

  company), since CG's off-shore parent Agfa has been absorbed by Miles.

  So typographically speaking, Compugraphic, CG, Agfa, A-G ag, and Miles

  all refer to the same company and font library. Their proprietary fonts

  are still CG Xyz, but the name is Miles Agfa.

Subject: 1.2. What's the difference between all these font formats?

  This question is not trivial to answer.  It's analogous to asking what

  the difference is between various graphics image file formats.  The

  short, somewhat pragmatic answer, is simply that they are different

  ways of representing the same "information" and some of them will work

  with your software/printer and others won't.

  At one level, there are two major sorts of fonts: bitmapped and outline

  (scalable).  Bitmapped fonts are falling out of fashion as various

  outline technologies grow in popularity and support.

  Bitmapped fonts represent each character as a rectangular grid of

  pixels.  The bitmap for each character indicates precisely what pixels

  should be on and off.  Printing a bitmapped character is simply a

  matter of blasting the right bits out to the printer.  There are a

  number of disadvantages to this approach.  The bitmap represents a

  particular instance of the character at a particular size and

  resolution.  It is very difficult to change the size, shape, or

  resolution of a bitmapped character without significant loss of quality

  in the image.  On the other hand, it's easy to do things like shading

  and filling with bitmapped characters.

  Outline fonts represent each character mathematically as a series of

  lines, curves, and 'hints'.  When a character from an outline font is

  to be printed, it must be 'rasterized' into a bitmap "on the fly".

  PostScript printers, for example, do this in the print engine.  If the

  "engine" in the output device cannot do the rasterizing, some front end

  has to do it first.  Many of the disadvantages that are inherent in the

  bitmapped format are not present in outline fonts at all.  Because an

  outline font is represented mathematically, it can be drawn at any

  reasonable size.  At small sizes, the font renderer is guided by the

  'hints' in the font; at very small sizes, particularly on

  low-resolution output devices such as screens, automatically scaled

  fonts become unreadable, and hand-tuned bitmaps are a better choice (if

  they are available).  Additionally, because it is rasterized "on

  demand," the font can be adjusted for different resolutions and 'aspect

  ratios'.

  Werenfried Spit adds the following remark:

  Well designed fonts are not scalable. I.e. a well designed 5pt font is

  not simply its 10pt counterpart 50% scaled down. (One can verify this

  by blowing up some small print in a copier and compare it with large

  print; or see the example for computer modern in D.E. Knuth's TeXbook.)

  Although this fact has no direct implications for any of the two

  methods of font representation it has an indirect one: users and word

  processor designers tend to blow up their 10pt fonts to 20pt or scale

  them down to 5pt given this possibility.  Subtle details, but well...

  LaserJet .SFP and .SFL files, TeX PK, PXL, and GF files, Macintosh

  Screen Fonts, and GEM .GFX files are all examples of bitmapped font

  formats.

  PostScript Type 1, Type 3, and Type 5 fonts, Nimbus Q fonts, TrueType

  fonts, Sun F3, MetaFont .mf files, and LaserJet .SFS files are all

  examples of outline font formats.

  Neither of these lists is even close to being exhaustive.

  To complicate the issue further, identical formats on different

  platforms are not necessarily the same.  For example Type 1 fonts on

  the Macintosh are not directly usable under MS-DOS or Unix, and

  vice-versa.

  It has been pointed out that the following description shows signs of

  its age (for example, the eexec encryption has been thoroughly hacked).

  I don't dispute the observation and I encourage anyone with the

  knowledge and time to submit a more up to date description.

  It has further been suggested that this commentary is biased toward

  Kingsley/ATF.  The omission of details about Bitstream (and possibly

  Bauer) may be considered serious since their software lies inside many

  3rd-party PostScript interpreters.

  The moderators of this FAQ would gladly accept other descriptions/

  explanations/viewpoints on the issues discussed in this (and every

  other) section.

  [Ed Note: Liam R. E. Quin supplied many changes to the following

  section in an attempt to bring it up to date.  Hopefully it is a better

  reflection of the state of the world today (12/07/92) than it was in

  earlier FAQs]