Re: ascender, descender, cap-height and x-height

At 01:56 PM 27-01-00 -0800, Erik van der Poel wrote:

>  P { font-family: Arial; font-size: 18px; }

>Suppose we have the Arial font. I.e. NO substitution. What, exactly,
>does "font-size: 18px" mean? Ascender + descender? TrueType's em? Or
>what?

It should refer to the font's scaled em height.

Using the ascender + descender is problematic for a number of reasons, not
least of which is that it is script specific. Insisting that
ascender+descender should equal the em height in the fonts is not only
meaningless for most of the world's writing systems, it can cause bad
clipping problems for diacritics with stacked accents, as is already seen
in Microsoft's WGL4 core fonts with stacked Danish diacritics.

John Hudson

Tiro Typeworks
Vancouver, BC
www.tiro.com
tiro@tiro.com

Received on Thursday, 3 February 2000 10:27:40 UTC