perm filename NOTES.TXT[CM,DEK]1 blob sn#798125 filedate 1985-07-08 generic text, type T, neo UTF8
Notes on the Computer Modern parameters

Dimensions are mostly in units of 1/36pt, because I originally worked
on graph paper with 36 pixels per point (in 1977). This experience made
me familiar with such units, so I later decided to make METAFONT produce
proofmode output at the same scale.

The basic fonts cmr5--cmr10 scale proportionately in most vertical
dimensions (e.g., the x_height in 5pt is half that in 10pt), but
horizontally the smaller fonts are more extended and have relatively
heavier weight (especially in hairlines).

The slanted fonts cmsl8--cmsl10 are identical to their unslanted
counterparts except that they have slant=1/6.

Font cmdunh10 is the same as cmr10 except that body_height, asc_height,
cap_height, and fig_height have been drastically increased.

The bold fonts cmbx5--cmbx10 have similar vertical dimensions to the ordinary
roman (except that the x_height is a bit taller and bar_height is lower);
they use bolder pen strokes, of course, and they are rather more extended.
Font cmb10 is like cmbx10 except not extended (i.e., 1em=10pt in cmb10,
but 1em=11.5pt in cmbx10); it also has slightly shorter cap serifs.  Font
cmbxsl10 is like cmbx10 but slanted.

The typewriter fonts cmtt8--cmtt10 have the same x_heights as their
roman counterparts, but they have shorter ascenders and longer descenders.
Their math_axis is based on ascenders only. The stroke weights are
almost all identical to the corresponding roman stem weight.
Font cmsltt10 is a slanted version of cmtt10.

A few isolated sans serif fonts appear in the standard set, as demonstrations
of how other varieties could be made. Font cmss10 is the normal weight
(corresponding to cmr10); its slanted equivalent is called cmssi10.
There's a demibold condensed version, cmssdc10, and a bold extended
version, cmssbx10. (The title pages in The TeXbook use cmssdc10 at 40pt
and a magnified version of cmssbx10 called cminch; to save font storage
space, cminch is restricted to digits and uppercase letters only.)
Finally, there's a pair of fonts called cmssq8 and cmssqi8; these are
in a rather different style (extended, with short ascenders and descenders),
used for the end-of-chapter quotations in The TeXbook.

The font cmfib8 is another `demonstration' of parameters; it's a serifed
font whose proportions are based on Fibonacci numbers. Also, the font
cmff10 is a weird concoction of little use except for testing.

The text italic fonts cmti7--cmti10 have parameters like their roman
cousins, except that they are more condensed and slightly lighter.
The math italic fonts cmmi5--cmmi10 are not condensed and not
quite as light.

Four special italic fonts are provided as demonstrations of further
possibilities: cmbxti10 is a bold extended text italic; cmmib10 is
a bold math italic; cmit10 is an italic typewriter font; cmu10 is
an unslanted italic with the same stem weights as cmr10.

The math symbol fonts, cmsy5--cmsy10, have the same parameters
as the corresponding math italic; these fonts also have special
parameters of their own. There's a bold math symbols font for
demonstration purposes: cmbsy10.

The math extension font, cmex10, has the parameters of cmr10.

The extended ASCII font, cmtex10, has the parameters of cmtt10, except
that the slant is positive (for a few characters that will be slanted).

And finally there are two caps-and-small-caps fonts, cmcsc10 (to match cmr10)
and cmtcsc10 (to match cmtt10). These fonts are unusual in having two
sets of parameters, one for the upper uppercase and one for the lower uppercase.