How to install OpenType fonts in LaTeX


LaTeX is the best typesetting system in the world and OpenType (.otf) fonts are some of the best in the world, but installing fonts in general is difficult in LaTeX.  It eluded me for several years but now I've succeeded.  (For the record, I use PDFeLaTeX in the MikTeX distribution with TeXnicCenter, but this should not make much difference.) Here's how:

1. Installing the fonts


I'll use a simple example, Adobe Caslon Pro, which comes in three weights divided into six files:
ACaslonPro-Bold.otf
ACaslonPro-BoldItalic.otf
ACaslonPro-Italic.otf
ACaslonPro-Regular.otf
ACaslonPro-Semibold.otf
ACaslonPro-SemiboldItalic.otf
The tool to use for the installation is Eddie Kohler's amazing otftotfm, available here. It's common advice to rename the files according to the Berry naming scheme.  This is useless---it's a lot of hard work to make everything more confusing.  The vendors' names might not be perfectly consistent, but they're at least as good as Berry and they make sense.  It's best to leave them alone.  As for encodings, LY1 seems to be best suited for OpenType.

Open Type and LaTeX have many, many features that, in my opinion, boil down into 4x12+1=49 different shapes (two axes plus ornaments; we'll use the following codes later):
Major axis:
  1. Roman (rm, r) - normal, upright text.
  2. Italic (it, i) - slanted, stylized text used for emphasis.
  3. Slanted (sl, s) - Roman letter forms slanted to match the Italics.  Some people hate them.  I found a very specialized use for them once: in my Ph.D. thesis, I set the names of object-oriented classes in slanted Roman, leaving normal text for the names of the concepts they represented. 
  4. UprightItalic (ui, u) - Italic letter forms slanted backwards to match the Romans.  A typographical freakshow?  Maybe, but maybe someone will find something other than a display use for them.
Minor axis:
  1. regular (rg) - the usual, normal shape.
  2. all-caps (ac) - doesn't change lowercase to uppercase (for the same reason that small-caps doesn't alter the capitals---because you might want to use the two together), it alters the spacing around caps and alters the punctuation to harmonize with capitals.
  3. small-caps (sc) - capital letter forms made to harmonize with lowercase.  Elegant, often used for abbreviations and headers.
  4. swashes (sw) - informal, calligraphic forms used for display.
  5. inferior figures (in) - small, low numbers---now you can speak elegantly about U235.
  6. superior figures (superscripts) (su) - useful for footnote marks and ordinal numbers.
  7. numerators (nu) - used in fractions.
  8. denominators (de) - used in fractions.
  9. proportional old-style figures (po) - different-width, lowercase numbers.
  10. proportional lining (pl) - different-width, uppercase numbers.
  11. tabular old-style figures (to) - monowidth, lowercase numbers.
  12. tabular lining figures (tl) - monowidth, uppercase numbers.
Tabular figures are monowidth so that they line up in tables. Proportional figures have better spacing.  Old-style figures look better in text.  Lining figures (all the same height, so they line up in that sense) are better, e.g., with all-caps headlines or for some special meaning (I use them for quantities). They look like two more axes, but they aren't, since the first four shapes must contain one default version of them.

That's the scheme we'll impose on the many OpenType options otftotfm can extract from the source files (you can read the otftotfm docs to find out more about these).  Here are the switches that go with the above shapes:
rm:
it:
sl: -S amt, where amt=the tangent of slant of the Italics
ui: -S -amt                   
rg: -fpnum -fonum
ac: -fcpsp -fcase -fpnum -flnum
sc: -fsmcp
sw: -fswsh
in: -fsinf
su: -fsups -fordn
nu: -fnumr
de: -fdnom
po: -fpnum -fonum
pl: -fpnum -flnum
to: -tnumf -fonum
tl: -tnumf -flnum
ornaments: -fornm
You can find out which features are available by examining the source files with otfinfo -f (also by Eddie Kohler),  but the above should work fine.  This is the stage where (by using switches) you select the default style of figures to use with the shapes rg, ac, sc and sw.  I use proportional lining figures with all-caps and swashes (since they're usually display) and proportional old-styles with regulars and small-caps, since they're usually text (actually, I leave the defaults for sc and sw to the discretion of the font designer, since sc and sw figures are conceivable); tabulars aren't useful outside of special situations like tables and lists. 

Here are all the otfmtotfm commands needed to install the three weights with the 49 options. I used other, standard switches, e.g., to enable ligatures and kerning. The -a switch should cause otftotfm to place everything where it belongs in your directory tree. The alt. selector character is used to select alternate stylistic forms of the same character if they exist, e.g., a calligraphic variant or an historical ligature. In your text, you might type c*t and get the old ligature, for example. I sacrificed the registered trademark character for this (it won't be usable otherwise now); this is easily changed. (Apparently, not all alternate forms can fit in the converted font---I notice some on the factory specimen sheet that I can't access.) To measure the slant to match the Slanted Romans to the Italics (and its opposite, to unslant the Italics), I measured the run/rise of the left edge of the left Italic bracket.  This worked fairly well, but apparently the lowercase Italics slant more than this, and so don't appear perfectly upright in their UprightItalic versions. If Uprights are very important to you, you might want to correct this---otftotfm has some options that might help.

2. Preparing the font description (.fd) file

The font description file is a LaTeX file that sits in your local texmf directory (somewhere like C:\localtexmf\tex\latex\lcdftools) and relates the font files you just installed to low-level selection commands like \fontshape{}\selectfont. My naming scheme is simple---I use trigraphs constructed from the shape codes above.  The first letter indicates the major axis and the remaining two indicate the minor axis.  I did something similar to separate the font series into two axes, weight and width.  So, my series are indicated by four letters, the first two indicating weight and the second two indicating width. So far, I've only defined the following; weight:
  1. light (lt)
  2. medium (md) (probably "book")
  3. semi-bold (sb)
  4. bold (bd)
  5. black (bl)
and width:
  1. condensed (cd)
  2. half-condensed (hc) (the odd name avoids a collision with sc)
  3. normal-width (nw)
  4. semi-extended (sx)
  5. extended (ex)
It shouldn't be difficult to add more as needed.

Here is my example .fd file, LY1ACaslonPro.fd (note the name of the encoding in the filename). Notice that some of the codes point to files you might not expect.  This is because the source font didn't contain all of the 48 possible variations, so I made substitutions.  For example: Slanted small-caps are substituted for Italic small-caps; UprightItalic swashes are substituted for Roman swashes. 

3. Without which, nothing.

Buried somewhere in the documentation, in a file not referred to anywhere that I know of is the following gem:  after preparing the above you must not only update TeX's filename database, but also make new map files.  Something like the following:
cd C:\localtexmf
initexmf -u
initexmf --mkmaps
initexmf -u
cd C:\texmf
initexmf -u
initexmf --mkmaps
initexmf -u

You must also do this after any change you make to the above steps.

4. Setting up a new NFSS

Now you'll want to use those OpenType features in LaTeX with a new new font selection scheme.  I've written a package to do this (unfortunately named "myfss"). Since I don't know plain TeX at all, the programming is strictly at the caveman level and it could surely be refined, but it all works. 

The main benefit of myfss is that it provides middle- and high-level selection commands for the separated series and shape axes.  The middle-level commands, like \bdexseries, \textbdex{} (bold extended) or \iscshape, \textisc{} (Italic small-caps) select specific series (weight/width combinations) or specific shapes with the four- or three-letter codes described above.  The high-level commands, like \ltweight, \textlt{} (light weight), \exwidth \textex{} (extended width), \uishape, \textui{} (UprightItalics), \toshape, \textto{} (tabular old-style) select weights, widths and the two shape axes independently.  For example, in a book on cinema, one might find a header set: "\scshape Fellini's \textit{Roma}".  All of this is done without breaking the old, familiar selection commands.  There is a selection for ornaments, but there is also a more convenient command, \ornament{<ornament number>}{<size>}{<baseline skip>}.

Several other niceties are provided:
Obviously, some of these come from my idiosyncrasies, but you can modify the package to suit yourself.  Also, this opens the possibility of setting "\scshape Fellini's \textit{\cvfrac{8}{1}{2}}".

5. Making a package for the particular font.

Here's my example of caslon.sty. It does three things:
  1. It sets up caslon as the default rm font.  You might want to make this optional.
  2. It maps the \char codes of the ornaments to the ornament numbers used by the myfss \ornament command.
  3. It fixes a few broken commands to access special characters.
The data for 2 and 3 were obtained during the next step.

6. Making a little specimen sheet.

A little document like this is great to use for testing.  I used it to search for ornament numbers, missing characters and alternate forms.  It includes a handy reference for LaTeX commands to access special characters.

Future extensions:

Yes, it would be nice to have a script that does all this automatically, but using copy, paste, find and replace, it's not too difficult---it's a pushbutton world.  Enjoy your fonts!  I have a lot to learn about installing fonts; comments and questions are welcome.  I'd be especially happy if anyone refined my code for the myfss.  o d r a d e k 5 \textat g m a i l.