Pica (unit of measure)

:"This page is for the unit of measure. For the eating disorder, see Pica (disorder). For other uses of the word Pica, see Pica."

A pica (IPAEng|ˈpaɪkə) is a typographic unit of measure corresponding to 1/72nd of its respective foot, and therefore to 1/6th of an inch. The pica contains 12 point units of measure.

The pica originated around 1785, when Françoise-Ambrose 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 0.013837in. (1/72.27in.), thus, a pica is 0.166044in. (4.2175mm)

* The contemporary computer pica is 1/72nd 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.

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) Fact|date=February 2007 Likewise, points are represented with number of points before a lower-case "p", for example, 5p represents “5 points”, and 6P2p represents “6 picas and 2 points”, and 1P1 represents “13 points”, which is converted to a mixed fraction of 1 pica and 1 point. Fact|date=February 2007

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.

Cascading Style Sheets defined by w3c use "pc' for the abbreviation for pica. Also

pt: points -- the points used by CSS2 are equal to 1/72th of an inch.
pc: picas -- 1 pica is equal to 12 points.

[http://www.w3.org/TR/REC-CSS2/syndata.html#length-units]

Note that these definitions are different from a typewriter's pica setting, which denotes a type size of ten characters per horizontal inch.

References

*cite book |title= "The Elements of Typographic Style", second edition |last=Bringhurst |first= Robert | year= 1999|publisher= H&M Publishers, pp. 294–295

*cite book |title= "American Dictionary of Printing and Bookmaking" |last=Pasko |first=W W |coauthors= |year= 1894|publisher= H. Lockwood, p. 436

See also

* Point (typography)

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