Point (typography)

Point
Unit system typographic unit
Unit of length
Unit conversions
1 point in ...... is equal to ...
   typographic units    1/12 picas
   imperial/US units    1/72 in
   metric (SI) units    0.3528 mm

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]

History

The point was first established by the Milanese typographer, Francesco Torniella da Novara (c.1490 – 1589) in his 1517 alphabet, L'Alfabeto. The construction of the alphabet is the first based on logical measurement called "Punto," which corresponds to the ninth part of the height of the letters or the thickness of the principal stroke.[3][4]

Notations

A measurement in points can be represented in three different ways. For example, 14 points (1 pica plus 2 points) can be written:

Varying standards

Various point definitions, sorted by size
Origin Year µm inch
Truchet 1694 ≈ 188 ≈ 0.007 400 48
JIS,[6] CSS q, DIN[7] 1976 = 250 ≈ 0.009 843 =  5⁄508
Fournier 1737 ≈ 345 ≈ 0.013 582 677
Johnson, ATA 1886 = 351.36 = 0.013 833 =  83⁄6000
Japan[8] 1962 = 351.4 ≈ 0.013 835
variant ≈ 351.406 ≈ 0.013 835
Hawks 1879 ≈ 351.456 = 0.013 837
TeX pt = 351.459 80 ≈ 0.013 837 =  100⁄7227
PS, CSS pt, TeX bp 1984 = 352.7 = 0.013 888 =  1⁄72
Tex nd[9] 1975 = 375 ≈ 0.014 764 =  15⁄1016
Tschichold ≈ 375.94 ≈ 0.014 801 =  250⁄16891
Didot 1770 ≈ 375.97 ≈ 0.014 802
Berthold = 376 ≈ 0.014 803 =  47⁄3175
TeX dd[10] ≈ 376.065 ≈ 0.014 806
Mozilla dt[11] 1997 = 376.296 = 0.014 8 =  2⁄135
Antenna House dd[12] ≈ 376.682 = 0.014 83
L’Imprimerie nationale = 400 ≈ 0.015 748

There have been many definitions of a “point” since the advent of typography. Traditional continental European points at about 375 µm are usually a bit larger than English points at around 350 µm.

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. At 9000 lines or 16 inches per foot, this established a length to the royal foot of 9000/27706 or ca. 325 mm, which made the Truchet point equal to 15625/83118mm or about 187.986 µm, although it has also been cited as exactly 188 µm.

The Fournier point established by Pierre Simon Fournier in 1737 [13] was about 11/864 French inches or (by 1799) 345 µm. This is very close to the present international point, but Fournier's point did not achieve lasting popularity despite being revived by the Monotype Corporation in 1927. It became standard in Belgium.

The system of Fournier was based on the Paris foot, 1 foot = 12 paris inches = 12 * 12 = lignes = 12 * 12 * 12 points. Two of these points became the Fournier-point. Fournier did cast his type on multiples of 3 points Fournier.

The Didot point established by François-Ambroise Didot in 1770. [14] was twice Truchet's and thus 1/864 of the royal foot, i.e. by 1799 15625/41559mm or ca. 375.971 µm.

12 point Founier equaled 11 point Didot, because of this the Fournier system was later called "median-system". This name "median" was used for type at 11 point.

Approximations 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.) Values included Hermann Berthold's 376 µm point and Jan Tschichold's 375.94 µm (266 points to 100 mm). Due to the definition in TeX of 1157 dd = 1238 pt, the slightly larger 376.065 µm became a common value.

TeX also supports a new Didot point (nd) at 3/8mm or 375 µm, and cites a 1978 redefinition for it.[9] The French National Print Office adopted a point of 2/5mm or 400 µm exactly and continues to use this measurement today. Japanese[6] and German[7] standardization bodies instead opted for a metric typographic base measure of exactly 1/4mm or 250 µm. It is called Q in Japanese after the initial letter of quarter millimetre. Due to demand by Japanese typesetters, CSS adopted Q in 2015.

The Didot point has been mostly replaced by the DTP point in Europe 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.[15] This is 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 0.013837 in (about 0.35146 mm). A variant was proposed to be exactly 83 picas or 996 points in 350 mm (ca. 0.351405622 mm/pt), giving it a value around 0.013848867 in.

The Johnson point was established by Lawrence Johnson in the mid-1800s 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 (ATA) approved the "Johnson pica" as its official standard in 1886, hence the alias ATA point. Following the 1959 standardization of the foot, this meant the American printer's foot was 303.5808 mm exactly and its point became 351.36 µm.

This size was approximated as exactly  1⁄72.27 of the modern inch[16] by Donald Knuth for the default unit of his TeX computer typesetting system and is thus sometimes known as the TeX point, which is 351.45980 µm, and exactly  800⁄803 of the PostScript point (bp in TeX).[17]

Like the French Didot point, the traditional American printer's point was largely replaced by the 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 352.7 µm. Twelve points make up a pica, and six picas make an inch. A separate typographic or printer's foot is not needed anymore.

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.[18][19]

In 1996, it was adopted by W3C for Cascading Stylesheets (CSS) where it was later related at a fixed 4:3 ratio to the pixel due to a general (but wrong) assumption of 96 px/in screens.

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"[20]—acquired traditional names in English, French, German, and Dutch, usually from their principal early uses.[21] 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;[21] metal type known as "agate" later ranged from 5 to 5.8 points. The sizes were gradually standardized as described above.[22] 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[23] British[20] French[24] German[25] Dutch Character Pinyin Meaning
1 American[26] Achtelpetit Achtste petit
1 1/2 German Achtelcicero Achtste cicero
2 Saxon Non Plus Ultra[28]
Viertelpetit 		Non plus ultra[29]
Vierde petit
2 1/2 Norse Microscopique[30] Microscopique[28] Microscoop
Microscopie
3 Excelsior[31][32] Minikin[31] Diamant Brillant[28]
Viertelcicero 		Kwart cicero
3 1/2 Ruby
Brilliant[34]
4 Brilliant Perle Diamant
Halbpetit[28] 		Robijn
Diamant
Halve petit
4 1/4 Gem
4 1/2 Diamond
5 Pearl Parisienne
Sédanoise 		Perl Parel
Parisienne		 八 Bā "Eight"
5 1/2 Agate Ruby[35][36] 七 Qī "Seven"
6 Nonpareil Nonpareille Nonpareille Nonparel
Nonpareil
6 1/2 Minionette[37] Emerald[37] Insertio Insertio 小六 Xiǎoliù "Little Six"
7 Minion Mignonne Kolonel Kolonel
Mignon
7 1/2 Petit-texte 六 Liù "Six"
8 Brevier Gaillarde
Petit-texte[34] 		Petit
Jungfer[34] 		Petit
Brevier[34]
9 Bourgeois[38] Petit-romain
Gaillarde[39] 		Bourgeois
Borgis[40] 		Borgis
Burgeois[39]		 小五 Xiǎowǔ "Little Five"
10 Long Primer Philosophie Korpus
Garmond[40] 		Corpus
Garamond
10 1/2 五 Wǔ "Five"
11 Small Pica Cicéro Rheinländer
Discendian[40] 		Mediaan
Rheinländer
12 Pica St.-Augustin Cicero Cicero
Augustijn		 小四 Xiǎosì "Little Four"
14 English Gros-texte[41]</ref> Mittel Grote cicero
Grote augustijn
Mediaan[42]		 四 Sì "Four"
15 Gros-texte[41] 小三 Xiǎosān "Little Three"
16 Columbian Gros-texte[41] Tertia Tertia 三 Sān "Three"
18 Great Primer Gros-romain 1 1/2 Cicero Paragon
Tekst[43]		 小二 Xiǎoèr "Little Two"
20 Paragon[21][23] Petit-parangon Text
Secunda[28]
22 Double Small Pica[21][23] 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[44] 		Dubbele tertia
36 Double Great Primer Trismégiste Kanon
Canon[28] 		Kanon 小初 Xiǎochū "Little Initial"
40 Double Paragon Doppeltext[45]
Große Kanon[46]
42 Seven-line Nonpareil Große Kanon[46] Grote Kanon 初 Chū "Initial"
44 Canon Gros-canon[47]</ref> Missal[48] Parijs Romein[49]
48 Four-line Pica
French canon		 Canon Gros-canon[47] Kleine Missal Konkordanz
Kleine missaal
54 Missal Missaal
56 Double-canon
60 Five-line pica Große Missal Sabon
66 Große Sabon[28] Grote sabon
72 Six-line pica
Inch 		Double-trismégiste Sabon
Sechscicero[28]
Kleine Sabon[45] 		6 cicero
84 Seven-line pica Siebencicero[28]
Große Sabon[45] 		7 cicero
88 Triple-canon
96 Eight-line pica Grosse-nonpareille Achtcicero[28]
Real[50] 		8 cicero
100 Moyenne de fonte
108 Nine-line pica Imperial[45] 9 cicero

See also

References

  1. ↑ Phinney, Thomas (16 August 2012). "Point Size and the Em Square: Not What People Think". Phinney on Fonts. Retrieved 24 February 2015.
  2. ↑ "Chapter 15: Fonts". Cascading Style Sheets Level 2 Revision 1 (CSS 2.1) Specification. 17 December 2014. § 15.8. Retrieved 24 February 2015.
  3. ↑ Giovanni Mardersteig (1971). The alphabet of Francesco Torniello da Novara [1517]: Followed by a comparison with the alphabet of Fra Luca Pacioli. Officina Bodoni.
  4. ↑ Healey, Robin (2011-01-01). Italian Literature Before 1900 in English Translation: An Annotated Bibliography, 1929-2008. University of Toronto Press. ISBN 9781442642690.
  5. ↑ http://www.w3.org/TR/REC-CSS2/syndata.html#length-units
  6. 1 2 JIS X 4052:2000, JIS Z 8125:2004
  7. 1 2 as an unnamed module first in DIN 16507-2:1984 and still in DIN 16507-2:1999
  8. ↑ JIS Z 8305
  9. 1 2 pdftex source code l. 10443 ff.
  10. ↑ "What are the various units (ex, em, in, pt, bp, dd, pc) expressed in mm?". Stacke Exchange.
  11. ↑ David Baron (2009-03-09). "Remove internal support for units that were never in CSS (feet, miles, meters, kilometers, didots, ciceros)". Mozilla.org.
  12. ↑ "AH Formatter: XSL/CSS Extensions". p. Extended Units.
  13. ↑ fr.wikipedia.org
  14. ↑ fr.wikipedia.org
  15. ↑ Public Law 39-183.
  16. ↑ Donald E. Knuth, The TeXbook, 17th revised printing, Addison-Wesley, 1990, p. 58
  17. ↑ pdftex source code l. 13773 ff.
  18. ↑ Tucker, H. A. (1988). "Desktop Publishing". In Ruiter, Maurice M. de. Advances in Computer Graphics III. Springer. p. 296. ISBN 3-540-18788-X.
  19. ↑ Spring, Michael B. (1991). Electronic printing and publishing: the document processing revolution. CRC Press. p. 46. ISBN 0-8247-8544-4.
  20. 1 2 Southward, John (1888), "Typography", Encyclopædia Britannica, 9th ed., Vol. XXIII, New York: Charles Scribner's Sons, p. 698.
  21. 1 2 3 4 5 Romano, Frank (Summer 2009). "The History of the Typographic Point" (PDF). APHA Newsletter (171): 3–4.
  22. ↑ "Type", Sizes.com, Santa Monica: Sizes Inc., 2004.
  23. 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.
  24. ↑ Pasko (1894), p. 215.
  25. ↑ Bauer, Friedrich (1929), Die Normung der Buchdrucklettern: Schrifthöhe, Schriftkegel, und Schriftlinie in ihrer geschichtlichen Entwichlung, Leipzig: Deutscher Buchgewerbeverein, p. 64. (in German)
  26. ↑ The existence of such small bodies was only notional in the age of metal type.[27]
  27. ↑ Pasko (1894), p. 18.
  28. 1 2 3 4 5 6 7 8 9 10 Bauer (1934).
  29. ↑ De Vinne (1900), p. 68.
  30. ↑ 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.
  31. 1 2 "minikin, n.¹ and adj.¹", Oxford English Dictionary, 3rd ed., Oxford: Oxford University Press, 2002.
  32. ↑ Note that the American name for 3-point type was initially "Brilliant"[23] and the English name was initially "Excelsior".[21] The American "Excelsior", meanwhile, was originally 4-point type.[23][33] The situation subsequently changed.
  33. ↑ "excelsior, n."'", Oxford English Dictionary, 1st ed., Oxford: Oxford University Press, 1894.
  34. 1 2 3 4 Pasko (1894), p. 70.
  35. ↑ "ruby, n.¹", Oxford English Dictionary, 3rd ed., Oxford: Oxford University Press, 2011
  36. ↑ Pasko (1894), p. 11.
  37. 1 2 "minionette, n.", Oxford English Dictionary, 3rd ed., Oxford: Oxford University Press, 2002.
  38. ↑ Pronounced "burjoyce".[39]
  39. 1 2 3 Pasko (1894), p. 65.
  40. 1 2 3 Pasko (1894), p. 229.
  41. 1 2 3 The French gros-texte referred indifferently to type sizes between 14 and 16 points.<ref name='FOOTNOTEPasko1894[http://www.columbia.edu/cu/lweb/digital/collections/cul/texts/ldpd_6062819_000/pages/ldpd_6062819_000_00000227.html 215]'>Pasko (1894), p. 215.
  42. ↑ Pasko (1894), p. 172.
  43. ↑ Pasko (1894), p. 238.
  44. ↑ von Bauer, Friedrich (1934), Handbuch für Schriftsetzer, Frankfurt: Verlag von Klimsch & Co.. (in German)
  45. 1 2 3 4 Staeck (1980).
  46. 1 2 The German Große Kanon referred indifferently to 40- or 42-point type.
  47. 1 2 The French gros-canon referred indifferently to type sizes of 44 or 48 points.<ref name='FOOTNOTEPasko1894[http://www.columbia.edu/cu/lweb/digital/collections/cul/texts/ldpd_6062819_000/pages/ldpd_6062819_000_00000227.html 215]'>Pasko (1894), p. 215.
  48. ↑ Pasko (1894), p. 79.
  49. ↑ Pasko (1894), p. 213.
  50. ↑ Staeck, Erich; et al. (1980), Rechenbuch für die Druckindustrie, Itzehoe: Verlag Beruf und Schule, ISBN 3-88013-155-4. (in German)
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