Re: "em" should be horizontal, "ex" vertical

Peter Flynn (
11 Aug 1997 10:59:50 +0100

Date: 11 Aug 1997 10:59:50 +0100
From: Peter Flynn <>
Message-id: <>
Subject: Re: "em" should be horizontal, "ex" vertical

> 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?