Pica (typography)

The pica is a typographic unit of measure corresponding to approximately  ¹⁄₆ of an inch, or  ¹⁄₇₂ of a foot. One pica is further divided into 12 points.

To date, in printing three pica measures are used:

• The French pica of 12 Didot points (also called cicéro) generally is: 12 × 0.376 = 4.512 mm (0.1776 in).

• The American pica of 0.016044 inches (0.4075 mm). It was established by the United States Type Founders' Association in 1886.^[1][2] In TeX one pica may be defined as  ¹²⁄_72.27 of an inch.

• The contemporary computer pica is exactly  ¹⁄₆ of a inch or  ¹⁄₇₂ of a foot, i.e. 4.233 mm or 0.166 inches.

Publishing applications such as Adobe InDesign and QuarkXPress represent pica measurements with whole-number picas left of a lower-case p, followed by the points number, for example: 5p6 represents 5 picas and 6 points, or 5 ¹⁄₂ picas.

Cascading Style Sheets defined by the World Wide Web Consortium use pc as the abbreviation for pica ( ¹⁄₆ of an inch), and pt for point ( ¹⁄₇₂ of an inch).^[3]

The pica is also used in measuring the font capacity and is applied in the process of copyfitting.^[4] The font length is measured there by the number of characters per pica (cpp). As books are most often printed with proportional fonts, cpp of a given font is usually a fractional number. For example, a 11-point font (like Helvetica) may have 2.4 cpp,^[5] thus a 5-inch (30-pica) line of a usual octavo-sized (6×8 in) book page would contain around 72 characters (including spaces).^[6][7]

The typographic pica must not be confused with the Pica font of the typewriters, which means a font where 10 typed characters make up a line one inch long.

See also

• Point (typography)
• Pitch (typewriter)

References

• Bringhurst, Robert (1999). The Elements of Typographic Style (2nd ed.). H&M Publishers. pp. 294–295. ISBN 0881791326. 
• Pasko, W. W. (1894). "Pica". American Dictionary of Printing and Bookmaking. H. Lockwood. p. 436.