Pica (typography)

{{short description|Unit of length}}

{{hatnote|Not to be confused with Pica, the traditional name for 12-point type.}}

{{Infobox unit

| image = File:The Evening Star ruler - 2.jpg

| caption = A ruler showing Pica scale (on the top) and Agate scale (on the bottom)

| name = Pica

| standard = Typographic unit

| quantity = Length

| units1 = typographic units

| inunits1 = 12 points

| units2 = imperial/US units

| inunits2 = {{sfrac|6}} in

| units3 = metric (SI) units

| inunits3 = {{convert|1/6|in|mm|4|disp=out|lk=on}}

}}

The pica is a typographic unit of measure corresponding to approximately {{frac|1|6}} of an inch. One pica is further divided into 12 points.

In printing, three pica measures are used:

• The French pica of 12 Didot points (also called cicero) generally is: 12 × 0.376 = {{cvt|4.512|mm|in}}.
• The American pica of {{cvt|0.16604|in|mm}}. It was established by the United States Type Founders' Association in 1886.{{cite book |last1=Legros |first1=Lucien Alphonse |last2=Grant |first2=John Cameron |title=Typographical Printing-Surfaces |date=1916 |publisher=Longmann, Green, and Co |location=London and New York |pages=57–60 |isbn=9785872323303 |url=https://books.google.com/books?id=yUkHAwAAQBAJ&pg=PA57}}{{cite book |last1=Hyde|first1=Grant Milnor |title=Newspaper Editing: A Manual for Editors, Copyreaders, and Students of Newspaper Desk Work |date=1920|publisher=D. Appleton and Company |location=New York and London |pages=226–227 |url=https://archive.org/stream/cu31924014523553#page/n241/mode/2up}} In TeX one pica is {{frac|400|2,409}} of an inch.
• The contemporary computer PostScript pica is exactly {{frac|1|6}} of an inch, i.e. 0.1{{overline|6}} in or 4.2{{overline|3}} mm.

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{{frac|1|2}} picas.

Cascading Style Sheets (CSS) defined by the World Wide Web Consortium use pc as the abbreviation for pica ({{frac|1|6}} of an inch), and pt for point ({{frac|1|72}} of an inch).{{cite web |url=http://www.w3.org/TR/REC-CSS2/syndata.html#length-units |title=Syntax and basic data types |publisher=W3.org |access-date=2016-10-21}}

The pica is also used in measuring the font capacity and is applied in the process of copyfitting.{{cite book |last1=Pipes |first1=Alan|title=Production for Graphic Designers |date=2005 |publisher=Laurence King Publishing|pages=48–49 |isbn=9781856694582|edition=4th |url=https://books.google.com/books?id=CdbH9hQSiHAC&pg=PA48}} 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,{{cite book |last1=Montagnes|first1=Ian|title=Editing and Publication: A Training Manual |date=1991|page=343|isbn=9789712200090|url=https://books.google.com/books?id=Ql0dNwaepjsC&pg=PA343}}{{cite book |last1=Newsom|first1=Doug |last2=Haynes |first2=Jim |title=Public Relations Writing: Form & Style |url=https://books.google.com/books?id=nXxzt8KMceAC&pg=PA392 |year=2010 |publisher=Cengage Learning |isbn=978-1-4390-8272-0 |pages=392–395}} thus a 5-inch (30-pica) line of a usual octavo-sized (6×8 in) book page would contain around 72 characters (including spaces).{{cite book |last1=Dahl|first1=Fred|title=Book Production Procedures for Today's Technology|date=2006|publisher=Inkwell Publishing Service |page=21|isbn=9781929163212|edition=2nd|url=https://books.google.com/books?id=lLw0spD7tZ0C&pg=PA21}}{{cite book|last1=Jackson|first1=Hartley Everett|title=Newspaper Typography, a Textbook for Journalism Classes|date=1942|publisher=Stanford University Press|pages=36–37|isbn=9780804710831|url=https://books.google.com/books?id=EeueAAAAIAAJ&pg=PA37}}

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.{{cite book|last1=Clair|first1=Kate|last2=Busic-Snyder|first2=Cynthia|title=A Typographic Workbook: A Primer to History, Techniques, and Artistry|url=https://books.google.com/books?id=Lf0iDYCr6w0C&pg=PA104|year=2012|publisher=John Wiley & Sons|isbn=978-1-118-39988-0|pages=101–104}}

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.