Picas and Points

Picas and Points

While one of us brandished a ruler festooned with picas to measure a design recently, it occurred to us that picas are likely alien to most people, though we use them throughout most of our work. Both picas and points are units of measurement that are peculiar to and invented for graphic design.

Given the ubiquity of word processors, most people are probably familiar with points from the context of font sizes. One point is equal to 1/72nd of an inch, or 0.3528 millimetres. Such a tiny unit of measurement is particularly useful in typography, which requires very meticulous adjustment.

Picas are a duodecimal unit of measurement, which means that they consist of 12 parts; one pica is equal to 12 points, which amounts to 1/6th of an inch or 4.2333 millimetres. A measurement in picas is written with a lowercase P distinguishing between whole picas and the remaining points. 1p6, for instance, describes 1.5 picas, or 18 points.