Type Sizes

by Ilene Strizver

What’s the point of a point system in which 24 points doesn’t always equal 24 points? It’s not pointless, but it does require some explanation!

What are points?

The point system is the standard unit of measurement for type. It originated centuries ago, when points referred to the size of the metal body that accommodated each character. Since each size of a typeface had to be cut individually, point size was determined by the distance from the height of the tallest ascender to the tip of the longest descender, plus a wee bit more.

The point system is still used today, although in digital type the original determining factors (ascenders and descenders) are not strictly adhered to. In print, 72 points equals about an inch. Does it then follow that all fonts set in 72 point look alike in size? Absolutely not! Here’s why: the actual appearance of a typeface at a particular size varies with the size of its ascenders, descenders and x-height. Therefore, a design with a tall x-height and/or short ascenders and descenders will usually look larger than one with opposite traits.

Choosing a point size

Because point size doesn’t tell you everything about how big a particular typeface will actually look, select type size optically. That is, let your eye guide you, not the numerical value of the font. Repeat the optical decision-making process every time you change typefaces, whether it’s for subheads, captions, lengthy quoted passages, or another reason. This is especially important in text sizes, where readability is strongly determined by point size.

When doing print work, always look at a printed sample before determining your final typeface sizes. Why? The low resolution of your computer monitor doesn’t display type accurately enough for this important decision!

NOTE: On the web, the height of a particular point size isn’t fixed as it is in print, but is dependent on the resolution of your monitor as well as the settings of your browser. Even so, the same relative differences exist from font to font.

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• Editor’s Note:Ilene Strizver, founder of The Type Studio, is a typographic consultant, designer and writer specializing in all aspects of typographic communication. She conducts Gourmet Typography workshops internationally. Read more about typography in her latest literary effort, Type Rules! The designer's guide to professional typography, 4th edition, published by Wiley & Sons, Inc. This article was commissioned and approved by Monotype Imaging Inc.