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Frequently Asked Questions About Fonts
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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
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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]