||This article needs additional citations for verification. (December 2010)|
|4.2333×10−3 m||4.23333 mm|
|US customary / Imperial units|
|13.889×10−3 ft||0.166667 in|
The pica originated around 1785, when François-Ambrose "L'éclat" Didot (1730–1804) refined the typographic measures system created by Pierre Simon Fournier le Jeune (1712–1768). He replaced the traditional measures of cicéro, Petit-Roman, and Gros-Text with “ten-point”, “twelve-point”, et cetera.
To date, in printing these three pica measures are used:
- The French pica of 12 Didot points (also called cicéro) generally is: 12 × 0.376 = 4.512mm (0.177in).
- The American pica measure of 0.013837 ft. (1⁄72.27 ft.). Thus, a pica is 0.166044in. (4.2175mm)
- The contemporary computer pica is 1⁄72 of the Anglo-Saxon compromise foot of 1959, i.e. 4.233mm or 0.166in. Notably, Adobe PostScript promoted the pica unit of measure that is the standard in contemporary printing, as in home computers and printers.
Note that these definitions are different from a typewriter's pica setting, which denotes a type size of ten characters per horizontal inch.
Usually, pica measurements are represented with an upper-case "P" with an upper-right-to-lower-left virgule (slash) starting in the upper right portion of the "P" and ending at the lower left of the upright portion of the "P"; essentially drawing a virgule ( / ) through a "P". (P̸) Likewise, points are represented with number of points before a lower-case "p", for example, 5p represents “5 points”, and 6P̸2p represents “6 picas and 2 points”, and 1P̸1 represents “13 points”, which is converted to a mixed fraction of 1 pica and 1 point.
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 5½ picas.
- Bringhurst, Robert (1999). The Elements of Typographic Style (Second ed.). H&M Publishers. pp. 294–295. ISBN 0881791326.
- Pasko, W. W. (1894). American Dictionary of Printing and Bookmaking. H. Lockwood. p. 436.