Non-Designer’s Type Book, The, Second Edition

The X-Height

The x-height of a typeface is the size of the body of the characters as epitomized by the letter x, since x is the only letter that reaches out to all four corners of the space.

It is the x-height that creates the impression of the font’s size. You see, the point size of the type as you know it, let’s say 24 point, originally referred to the size of the little piece of metal on which the letter was created. Within that 24-point space, the designer could do anything he wanted—he could make tall ascenders, a large x-height, a small x-height, short descenders. He didn’t even have to take up the whole 24-point space. So when we say ...