[comp.lang.postscript] Hints, Was: Doubling Font sizes and Shrinking Photographically

pgd@bbt.se (11/17/90)

In article <1990Nov13.174531.11434@ux1.cso.uiuc.edu> khcg0492@uxa.cso.uiuc.edu (Kenneth Holden Chang) writes:
>Correct me if I'm wrong, but this is *not* what the hints do, and is indeed
>one of the drawbacks of Postscript. What the "hints" do is adjust for low
>resolution (300 dpi) printers. Otherwise the letters tend to look "heavy."
>On a high-resolution printer like a Linotronic, however, fonts are scaled
>exactly, that is a 48 point 'A' looks exactly like a 24 point 'A' except it's
>larger. This is also Adobe's Expert Collections contain what are called
>"Titling" characters, i.e. fonts designed for larger point sizes.

I actually made an experiment by taking an Adobe font, converting it to
Type 3 format (without hints), and made printout both with, and
without hints, on both a laser printer (400 dpi), and a Linotronic 300
(1270dpi).

The Linotronic outputs show no difference.

The laser-printouts are different. The non-hinted printout looks
"uglier". A nearer examination shows the differences:
The letters tend to jump on the baseline. This is due to letters like
o, a, s, which decend a little bit on the hinted printout, but not on
the non-hinted. The non-hinted letters are more misformed, and look
more jagged. One example is shallow curves, like on the serifs.
The positioning of straight lines also are less accurate on the
non-hinted fonts. Each letter might be allright, but the overall
appearence of a line of text, is worse. The letters tend to differ
more from each other, without hints.

So, the hints just compensate for rasterization errors on
low-resolution devices (like laser-printers). The hints tend to
preserve the letter forms, instead of mathematical correctness. That
makes the letters look nicer to the eye.