Re: "em" should be horizontal, "ex" vertical
Peter Flynn wrote at 11/8/97 10:59 am
>> While that's a good definition, typesetting practice /never/ uses "em"
>> as vertical measurement; an em is a horizontal measurement only, and an
>> "ex" is the vertical measurement. This makes measurements based on
>> fonts size work with compressed an/or fat fonts.
>This is incorrect: pica ems are used for page depth and line spacing
>almost universally in the Anglo-American world. When did you last see
>a comp's spec specify print-area height in "ex"s?
Correct, the definition of an "em" is a *square* of any given body size,
ie 9pt*9pt, 24pt*24pt, 72pt*72pt are all ems. The correct term for a 12pt
em is a *pica* em as pointed out, an em is a relative unit.