The pica is a typographic unit of measure corresponding to approximately 1⁄6 of an inch, or from 1⁄68 to 1⁄73 of a foot. One pica is further divided into 12 points.
| Pica | |
|---|---|
 A ruler showing Pica scale (on the top) and Agate scale (on the bottom) | |
| General information | |
| Unit system | Typographic unit |
| Unit of | Length |
| Conversions | |
| 1 pica in ... | ... is equal to ... |
| typographic units | 12 points |
| imperial/US units | 1/6 in |
| metric (SI) units | 4.2333 mm |
In printing, three pica measures are used:
- The French pica of 12 Didot points (also called cicero) generally is: 12 × 0.376 = 4.512 mm (0.1776 in).
- The American pica of 0.16604 inches (4.217 mm). It was established by the United States Type Founders' Association in 1886.[1][2] In TeX one pica is 400⁄2,409 of an inch.
- The contemporary computer PostScript pica is exactly 1⁄6 of an inch or 1⁄72 of a foot, i.e. 4.23 mm or 0.16 in.
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 51⁄2 picas.
Cascading Style Sheets (CSS) 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, an 11-point font (like Helvetica) may have 2.4 cpp,[5][6] thus a 5-inch (30-pica) line of a usual octavo-sized (6×8 in) book page would contain around 72 characters (including spaces).[7][8]
There have existed copyfitting tables for a number of typefaces, and typefoundries often provided the number of characters per pica for each type in their specimen catalogs. Similar tables exist as well with which one can estimate the number of characters per pica knowing the lower-case alphabet length.[9]
The typographic pica should 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
editReferences
edit- ^ Legros, Lucien Alphonse; Grant, John Cameron (1916). Typographical Printing-Surfaces. London and New York: Longmann, Green, and Co. pp. 57–60. ISBN 9785872323303.
- ^ Hyde, Grant Milnor (1920). Newspaper Editing: A Manual for Editors, Copyreaders, and Students of Newspaper Desk Work. New York and London: D. Appleton and Company. pp. 226–227.
- ^ "Syntax and basic data types". W3.org. Retrieved 2016-10-21.
- ^ Pipes, Alan (2005). Production for Graphic Designers (4th ed.). Laurence King Publishing. pp. 48–49. ISBN 9781856694582.
- ^ Montagnes, Ian (1991). Editing and Publication: A Training Manual. p. 343. ISBN 9789712200090.
- ^ Newsom, Doug; Haynes, Jim (2010). Public Relations Writing: Form & Style. Cengage Learning. pp. 392–395. ISBN 978-1-4390-8272-0.
- ^ Dahl, Fred (2006). Book Production Procedures for Today's Technology (2nd ed.). Inkwell Publishing Service. p. 21. ISBN 9781929163212.
- ^ Jackson, Hartley Everett (1942). Newspaper Typography, a Textbook for Journalism Classes. Stanford University Press. pp. 36–37. ISBN 9780804710831.
- ^ Clair, Kate; Busic-Snyder, Cynthia (2012). A Typographic Workbook: A Primer to History, Techniques, and Artistry. John Wiley & Sons. pp. 101–104. ISBN 978-1-118-39988-0.
- 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.