Point (typography)
SI units | |
---|---|
352.78×10 −6 m | 352.778 μm |
US customary units (Imperial units) | |
1.1574×10 −3 ft | 13.889×10 −3 in |
In typography, the point is the smallest unit of measure. It is used for measuring font size, leading, and other items on a printed page. The size of the point has varied throughout the history of printing. Since the 18th century, the point's size has varied from 0.18 to 0.4 millimeters. Following the advent of desktop publishing in the 1980s and 1990s, digital printing has largely supplanted the letterpress printing and has established the DTP point (desktop publishing point) as the de facto standard. The DTP point is defined as 1⁄72 of an international inch (about 0.353 mm) and, as with earlier American point sizes, is considered to be 1⁄12 of a pica.
In metal type, the point size of the font described the height of the metal body on which the typeface's characters were cast. In digital type, letters of a font are designed around an imaginary space called an em square. When a point size of a font is specified, the font is scaled so that its em square has a side length of that particular length in points. Although the letters of a font usually fit within the font's em square, there is not necessarily any size relationship between the two, so the point size does not necessarily correspond to any measurement of the size of the letters on the printed page.[1][2]
Notations
A measurement in points can be represented in three different ways. For example, 14 points (1 pica plus 2 points) can be written:
- 1P̸2p (12 points would be just "1P̸")—traditional style
- 1p2 (12 points would be just "1p")—format for desktop
- 14pt (12 points would be "12pt" or "1pc" since it is the same as 1 pica)—format used by Cascading Style Sheets defined by the World Wide Web Consortium[3]
Varying standards
There have been many definitions of a “point” since the advent of typography.
Name | Year | mm | inch |
---|---|---|---|
Truchet | 1694 | ≈0.187 972 186 | ≈0.007 400 48 |
Fournier | 1737 | ≈0.345 | ≈0.013 582 677 |
Didot | 1770 | ≈0.375 971 51 | ≈0.014 802 028 |
European printers' offices | ... | =0.376 065 | ≈0.014 805 709 |
Berthold | ... | =0.376 | ≈0.014 803 15 |
Tschichold | ... | =0.375 94 | ≈0.014 800 787 |
1975 proposal | 1975 | =0.375 | ≈0.014 763 78 |
French National Print Office | ... | =0.4 | ≈0.015 748 031 |
Hawks | 1879 | ≈0.35146 | =0.013 837 |
Johnson | 1886 | =0.351 459 80 mm | =0.01383 |
Desktop publishing | 1984 | =0.3527 | 1⁄72 |
French points
The Truchet point, the first modern typographic point, was 1⁄144 of a French inch or 1⁄1728 of the royal foot. It was invented by the French clergyman Sébastien Truchet. During the metrication of France amid its revolution, a 1799 law declared the meter to be exactly 443.296 French lines long, establishing a length to the royal foot of 9,000⁄27,706 or 0.325 m. This made the Truchet Point equal to 15,625⁄83,124 or 0.187 972 186 mm.
The Fournier point established by Pierre Simon Fournier was about 11⁄864 French inches or (by 1799) 0.345 mm. This is very close to the present international point described above, but Fournier's point did not achieve lasting popularity despite being revived by the Monotype Corporation in 1927. It became standard in Belgium.
The Didot point established by François-Ambroise Didot was twice Truchet's and thus 1⁄864 of the royal foot or (by 1799) 15,625⁄41,559 or 0.375 971 51 mm.
Other French points were subsequently employed, largely owing to the Didot point's unwieldy conversion to metric units. (The divisor of its conversion ratio has the prime factorization of 3 × 7 × 1979.) The standard value in European printers' offices came to be the slightly larger 0.376 065 mm'. Other values included Hermann Berthold's 0.376 mm point, Jan Tschichold's 0.375 94 mm (266 points to 100 mm), and a generally ignored proposal to use 0.375 mm offered in 1975. The French National Print Office adopted a point of 0.4 mm exactly and continues to use this measurement today.
The Didot point has been replaced by the DTP point in France and throughout the world.
American points
A typographic or printer's foot contains 72 picas or 864 points. The Metric Act of 1866 established a legal ratio of 1200 : 3937 between the foot and the meter.[4] For the survey foot used prior to 1959, this was 0.0002% more than 304.8 mm, the length of the international foot established by the 1959 International Yard and Pound Agreement.
The Hawks point was established by Nelson Hawks in 1879, based on a printer's foot reduced by 0.375% from the standard foot of his time. It had a value of 0.013 837 inch (about 0.35146 mm).
Another point was proposed to be exactly 996 points or 83 picas in 350 mm, giving it a value around 0.013 848 867 inch (0.351 405 622 mm).
The Johnson point was established by Lawrence Johnson based on a printer's foot 249⁄250 as large as the standard foot (11.952 inches or 0.996 foot). It thus had a value of 0.01383 inch. The 15th meeting of the Type Founders Association of the United States approved the "Johnson pica" as its official standard in 1886. Following the 1959 standardization of the foot, this meant the American printer's foot was 303.5808 mm exactly. This size was used by Donald Knuth's TeX computer typesetting system and is thus sometimes known as the TeX point, which is exactly 0.35145980 mm, or exactly 1⁄72.27 of the modern (post-1959) inch, or exactly 800⁄803 of the PostScript point (bp in TeX).[5]
Like the French Didot point, the traditional American printer's point was replaced in the 1980s by the current computer-based DTP point system.
Desktop publishing point
The desktop publishing point (DTP point) or PostScript point is defined as 1⁄72 or 0.0138 of the international inch, making it equivalent to 0.3527 mm. Twelve points make up a pica, and six picas make an inch.
This specification was developed by John Warnock and Charles Geschke when they created Adobe PostScript. It was adopted by Apple Computer as the standard for the display resolution of the original Macintosh desktop computer and the print resolution for the LaserWriter printer.[6][7]
Point-size names
Fonts originally consisted of a set of moveable type letterpunches purchased from a type foundry. As early as 1600, the sizes of these types—their "bodies"[8]—acquired traditional names in English, French, German, and Dutch, usually from their principal early uses.[9] These names were used relative to the others and their exact length would vary over time, from country to country, and from foundry to foundry. For example, "agate" and "ruby" used to be a single size "agate ruby" of about 5 points;[9] metal type known as "agate" later ranged from 5 to 5.8 points. The sizes were gradually standardized as described above.[10] Modern Chinese typography uses the following names in general preference to stating the number of points. In ambiguous contexts, the word hào (t 號, s 号, lit. "number") is added to the end of the size name to clarify the meaning.
Note that the Chinese font sizes use American points; the Continental systems traditionally used the Fournier or Didot points. The Fournier points, being smaller than Didot's, were associated with the names of the Didot type closest in size rather than identical in number of points.
Point | American system | Continental system | Chinese system | |||||
---|---|---|---|---|---|---|---|---|
American[11] | British[8] | French[12] | German[13] | Dutch | Character | Pinyin | Meaning | |
1 | American[14] | Achtelpetit | Achtste petit | |||||
1½ | German | Achtelcicero | Achtste cicero | |||||
2 | Saxon | Non Plus Ultra[16] Viertelpetit | Non plus ultra[17] Vierde petit |
|||||
2½ | Norse | Microscopique[18] | Microscopique[16] | Microscoop Microscopie |
||||
3 | Excelsior[19][20] | Minikin[19] | Diamant | Brillant[16] Viertelcicero | Kwart cicero | |||
3½ | Ruby Brilliant[22] | |||||||
4 | Brilliant | Perle | Diamant Halbpetit[16] | Robijn Diamant Halve petit |
||||
4¼ | Gem | |||||||
4½ | Diamond | |||||||
5 | Pearl | Parisienne Sédanoise | Perl | Parel Parisienne |
八 | Bā | "Eight" | |
5½ | Agate | Ruby[23][24] | 七 | Qī | "Seven" | |||
6 | Nonpareil | Nonpareille | Nonpareille | Nonparel Nonpareil |
||||
6½ | Minionette[25] | Emerald[25] | Insertio | Insertio | 小六 | Xiǎoliù | "Little Six" | |
7 | Minion | Mignonne | Kolonel | Kolonel Mignon |
||||
7½ | Petit-texte | 六 | Liù | "Six" | ||||
8 | Brevier | Gaillarde Petit-texte[22] | Petit Jungfer[22] | Petit Brevier[22] |
||||
9 | Bourgeois[26] | Petit-romain Gaillarde[27] | Bourgeois Borgis[28] | Borgis Burgeois[27] |
小五 | Xiǎowǔ | "Little Five" | |
10 | Long Primer | Philosophie | Korpus Garmond[28] | Corpus Garamond |
||||
10½ | 五 | Wǔ | "Five" | |||||
11 | Small Pica | Cicéro | Rheinländer Discendian[28] | Mediaan Rheinländer |
||||
12 | Pica | St.-Augustin | Cicero | Cicero Augustijn |
小四 | Xiǎosì | "Little Four" | |
14 | English | Gros-texte[29] | Mittel | Grote cicero Grote augustijn Mediaan[30] |
四 | Sì | "Four" | |
15 | Gros-texte[29] | 小三 | Xiǎosān | "Little Three" | ||||
16 | Columbian | Gros-texte[29] | Tertia | Tertia | 三 | Sān | "Three" | |
18 | Great Primer | Gros-romain | 1½ Cicero | Paragon Tekst[31] |
小二 | Xiǎoèr | "Little Two" | |
20 | Paragon[9][11] | Petit-parangon | Text Secunda[16] | |||||
22 | Double Small Pica[9][11] | Gros-parangon | 二 | Èr | "Two" | |||
24 | Double Pica | Palestine | Doppelcicero | Dubbele cicero Palestine |
小一 | Xiǎoyī | "Little One" | |
26 | 一 | Yī | "One" | |||||
28 | Double English | Petit-canon | Doppelmittel | Dubbele mediaan | ||||
30 | Five-line Nonpareil | |||||||
32 | Double Columbian | Kleine Kanon Doppeltertia[32] | Dubbele tertia | |||||
36 | Double Great Primer | Trismégiste | Kanon Canon[16] | Kanon | 小初 | Xiǎochū | "Little Initial" | |
40 | Double Paragon | Doppeltext[33] Große Kanon[34] | ||||||
42 | Seven-line Nonpareil | Große Kanon[34] | Grote Kanon | 初 | Chū | "Initial" | ||
44 | Canon | Gros-canon[35] | Missal[36] | Parijs Romein[37] | ||||
48 | Four-line Pica French canon |
Canon | Gros-canon[35] | Kleine Missal | Konkordanz Kleine missaal |
|||
54 | Missal | Missaal | ||||||
56 | Double-canon | |||||||
60 | Five-line pica | Große Missal | Sabon | |||||
66 | Große Sabon[16] | Grote sabon | ||||||
72 | Six-line pica Inch | Double-trismégiste | Sabon Sechscicero[16] Kleine Sabon[33] | 6 cicero | ||||
84 | Seven-line pica | Siebencicero[16] Große Sabon[33] | 7 cicero | |||||
88 | Triple-canon | |||||||
96 | Eight-line pica | Grosse-nonpareille | Achtcicero[16] Real[38] | 8 cicero | ||||
100 | Moyenne de fonte | |||||||
108 | Nine-line pica | Imperial[33] | 9 cicero | |||||
See also
References
- ↑ Phinney, Thomas (16 August 2012). "Point Size and the Em Square: Not What People Think". Phinney on Fonts. Retrieved 24 February 2015.
- ↑ "Chapter 15: Fonts". Cascading Style Sheets Level 2 Revision 1 (CSS 2.1) Specification. 17 December 2014. § 15.8. Retrieved 24 February 2015.
- ↑ http://www.w3.org/TR/REC-CSS2/syndata.html#length-units
- ↑ Public Law 39-183.
- ↑ pdftex source code l. 13773 ff.
- ↑ Tucker, H. A. (1988). "Desktop Publishing". In Ruiter, Maurice M. de. Advances in Computer Graphics III. Springer. p. 296. ISBN 3-540-18788-X.
- ↑ Spring, Michael B. (1991). Electronic printing and publishing: the document processing revolution. CRC Press. p. 46. ISBN 0-8247-8544-4.
- 1 2 Southward, John (1888), "Typography", Encyclopædia Britannica, 9th ed., Vol. XXIII, New York: Charles Scribner's Sons, p. 698.
- 1 2 3 4 5 Romano, Frank (Summer 2009). "The History of the Typographic Point" (PDF). APHA Newsletter (171): 3–4.
- ↑ "Type", Sizes.com, Santa Monica: Sizes Inc., 2004.
- 1 2 3 4 5 Pasko, Wesley Washington, ed. (1894), American Dictionary of Printing and Bookmaking, Containing a History of These Arts in Europe and America, with Definitions of Technical Terms and Biographical Sketches, New York: Howard Lockwood & Co., p. 522.
- 1 2 3 Pasko (1894), p. 215.
- ↑ Bauer, Friedrich (1929), Die Normung der Buchdrucklettern: Schrifthöhe, Schriftkegel, und Schriftlinie in ihrer geschichtlichen Entwichlung, Leipzig: Deutscher Buchgewerbeverein, p. 64. (German)
- ↑ The existence of such small bodies was only notional in the age of metal type.[15]
- ↑ Pasko (1894), p. 18.
- 1 2 3 4 5 6 7 8 9 10 Bauer (1934).
- ↑ De Vinne (1900), p. 68.
- ↑ De Vinne, Theodore Low (1900), The Practice of Typography: A Treatise on the Processes of Type-Making, the Point System, the Names, Sizes, Styles, and Prices of Plain Printing Types, New York: The Century Co., p. 68.
- 1 2 "minikin, n.¹ and adj.¹", Oxford English Dictionary, 3rd ed., Oxford: Oxford University Press, 2002.
- ↑ Note that the American name for 3-point type was initially "Brilliant"[11] and the English name was initially "Excelsior".[9] The American "Excelsior", meanwhile, was originally 4-point type.[11][21] The situation subsequently changed.
- ↑ "excelsior, n."'", Oxford English Dictionary, 1st ed., Oxford: Oxford University Press, 1894.
- 1 2 3 4 Pasko (1894), p. 70.
- ↑ "ruby, n.¹", Oxford English Dictionary, 3rd ed., Oxford: Oxford University Press, 2011
- ↑ Pasko (1894), p. 11.
- 1 2 "minionette, n.", Oxford English Dictionary, 3rd ed., Oxford: Oxford University Press, 2002.
- ↑ Pronounced "burjoyce".[27]
- 1 2 3 Pasko (1894), p. 65.
- 1 2 3 Pasko (1894), p. 229.
- 1 2 3 The French gros-texte referred indifferently to type sizes between 14 and 16 points.[12]
- ↑ Pasko (1894), p. 172.
- ↑ Pasko (1894), p. 238.
- ↑ von Bauer, Friedrich (1934), Handbuch für Schriftsetzer, Frankfurt: Verlag von Klimsch & Co.. (German)
- 1 2 3 4 Staeck (1980).
- 1 2 The German Große Kanon referred indifferently to 40- or 42-point type.
- 1 2 The French gros-canon referred indifferently to type sizes of 44 or 48 points.[12]
- ↑ Pasko (1894), p. 79.
- ↑ Pasko (1894), p. 213.
- ↑ Staeck, Erich; et al. (1980), Rechenbuch für die Druckindustrie, Itzehoe: Verlag Beruf und Schule, ISBN 3-88013-155-4. (German)
External links
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