The terms font size , font size , Schriftsatzmaß or cone height (also bowling strength ) indicate in the typography a measure of the size of a font. The cone (picture number 6) is in the lead sentence of the body carrying the slightly smaller, mirror image of the letter (no. 2). The height of the cone (distance d) denotes the height of the lead cone. Since the cones are slightly higher than the letters, the cone height or the font size is always slightly larger than the sum of the upper, middle and lower length and therefore larger than the actual letter size.
Different units of measurement are used for the font size and are usually referred to as " point " (pt). These units of measurement are used in print products not only for the font size, but also for line spacing and the like.
The dimensions are set out in DIN 16507-1 (currently as of September 1998 ).
Optical font size
Since the font size only describes the cone height (also with fonts ), it says nothing about the visual impression of the font size. This is mainly dependent on the center length of the font. If the font has a particularly small upper and lower length, the middle length on the font is proportionally larger, as the font designer usually uses the entire height of the cone with the span between the upper and lower length.
Script fonts with particularly extravagant ascenders and descenders (such as the Bickham Script) therefore often appear very small. For the same reason, the assumption that Antiqua typefaces generally look smaller than Grotesque typefaces is wrong. This only applies to the comparison of classical antiqua (such as Garamond) with classical grotesques (such as Helvetica), or of antiqua and grotesques with comparable metrics .
Units of the measurement system
The point (p) is the basic unit for specifying font sizes.
The first typographical measurement system was conceived in 1695 by Sébastien Truchet (1657–1729) of the French Academy of Sciences . He took the royal Paris foot ( Pied de Roi , "king's foot") of about 32.484 cm, which was defined as one sixth of the Paris Toise ( fathom ), the iron standard rod Toise du Grand Châtelet , which is valid in Paris . One foot ( pied ) was divided into 12 inches and one inch ( pouce ) into 12 lines . Trouchet now called a twelfth of the Paris line ( Ligne ) a Ligne seconde ("second line"), this was about 0.188 mm. However, the ligne seconde should not find general distribution.
Since around 1737, the French printer Pierre Simon Fournier called one sixth of the line he used a point typographique ("typographical point"), assuming a foot of only around 29.8 cm, as the length of the Toise varies regionally in France and thus also of the foot. This so-called Fournier point (about 0.345 mm) was later no longer used.
In 1766 a copy of the Toise du Grand Châtelet made in 1735 , the original probably disappearing through theft in 1755, was declared the prototype of the legal measure of length throughout France.
At the end of the 18th century, François Ambroise Didot and his son Firmin Didot further developed the typographic measurement system. The Didot point , which later became established throughout Europe , corresponded to one sixth of the Paris line, i.e. about 0.375972 mm (traditionally 0.376065 mm). It is usually specified as 0.376 mm and is also used that way, as this is well within all technical tolerances. As with Truchet, the basic dimension was the Paris foot, so 12 × 12 × 6 = 864 Didot points are exactly one Paris foot.
In 1975 the ISO set the Didot point to be exactly 0.375 mm. For use with the existing printing machines, however, a modification of more than a quarter percent was significant and therefore technically too difficult to implement. In addition, at that time the photo typesetting technique was being used, so this proposal was never fully implemented in practice, although officially a Didot point is 3 ⁄ 8 mm.
At the end of the 19th century, with the invention of the Linotype line casting machine, an alternative point size came to Europe from the USA : the pica point (pp). The American printers used their own American "printer foot ", which corresponds to exactly 1024/1000 Roman feet , i.e. about 303.5 mm.
Of three competing, almost identical definitions, the 15th meeting of the US Type Founders Association of the USA (1886) passed the so-called Johnson Pica at exactly 0.166 inches . Nelson C. Hawks' suggestion (1200/7227 in / pt ≈ 0.166044 in / pc) and the direct reference to the metric system (83/350 pc / mm ≈ 0.1660184 in / pc) were not taken into account.
Analogous to the ratio of Cicero to Didot point, a pica is divided into 12 points. Therefore the traditional American printer's point measures 351.3 6 µm.
In some sources the American point is given as (approximately) 100/7227 inch, that would be approx. 351.4598 µm and corresponds to the definition according to Hawks. The metric point would be approximately 351.4056 µm.
In desktop publishing (DTP) today, a simplified definition of the American point is used almost exclusively.
The DTP point , abbreviated to 'pt', sometimes also called PostScript point, was defined as the 864th part of the English foot of 1959. So it measures exactly 1 ⁄ 72 inch, i.e. H. 0.013 8 inches or 0.352 7 mm. It is currently the only reliable measure in most application programs ( printer communication , Word , Draw , Photoshop, etc. - Calamus and CorelDraw, on the other hand, were programmed metrically).
In CSS , this point is also set in a simple ratio of 4: 3 to the reference pixel 'px', which does not necessarily correspond to the device pixel.
With a dot density of 300 dpi, which is often found in home printing, a DTP dot then corresponds to approximately four image points in the reproduction. A character with 12 pt is printed in height under these conditions with 50 pixels.
The German standard DIN 16507-2: 1999 provides a module of 250 µm for font size specifications and line heights in electronic typesetting , with a sub- module of 50 µm for intermediate sizes . This module is sometimes used like a unit corresponding to the point and is then called a quart ('q'), since it corresponds to a quarter of a millimeter, and is particularly common in Japan as キ ュkyu . As
qif it was also part of CSS from level 3 .
Instead of the cone height, DIN 16507-2 uses the measurable size of the capital height to indicate the font size. This system has not found widespread use up to now, but different computer typography languages (e.g. TeX, CSS , Framemaker ) support the measurement in metric units.
Otl Aicher was one of the proponents of this system and propagated font sizes, some of which are based on traditional names.
In addition to the absolute font sizes, in which a specific length can be assigned to a font size, there is also a measurement in pixels (px) in computer graphics . While the real size of a pixel in devices is determined by the design, there may be surprises when printing a font size specified in pixels if the assignment is not determined. Therefore z. For example, with CSS for pixel values a conversion in DTP of 1 inch = 72 pt = 96 pixels is specified. This assigns an absolute font size to the relative font size. Other units defined in CSS, such as em and ex, relate to the font currently in use and can therefore only be converted by defining an absolute font size.
Table of font sizes
In the metal type age, each font size had to be cut separately. The names used therefore refer to absolute quantities and not to specific point specifications in any system. This explains the shift in French names between Fournier and Didot points.
|German||French||fp||mm||dd||old (mm)||new (mm)||pt||Pica (mm)||DTP (mm)||English|
|Body / Garmond||philosophy||11||3.74||10||3.76||3.75||10||3.51||3.53||Long primer|
From a font size of 4 points, the " German normal font" applies . The distinction “coarse” in front of the font name often indicates a lowering of the baseline in order to accommodate a somewhat larger (coarser) font on a cone of the same height.
In German, other terms were sometimes used for the Didot grades: Non Plus Ultra (2 Didot point), Microscopique (2½), Insertio (6½), Paragon (18), Text (20), Canon (36, small: 32, coarse: 42), concordance (48), missal (small: 48, coarse: 54), sabon (60) and the prefix double for Cicero (24), medium (28) and tertia (32).
From the "Kanon" (36 points) upwards, the German names did not always refer to the same font. You can find “Canon” for 32 and 36 points, “Grobe Kanon” for 40 and 42 points, “Missal” even for 48, 54 and 60 points. "Sabon" and designations of greater degrees always stood for different cone heights.
- Jan Tschichold: Pleasing printed matter through good typography , chapter The typographical measurement system. Maro, Augsburg 2001, ISBN 3-87512-413-8 , from p. 53.
- Claudia Runk: Basic course in typography and layout . Section 1.7: Typographic measurement system . Galileo, Bonn 2006, ISBN 3-89842-406-5 , pp. 79 and 80.
- Eberhard Dilba: Typography lexicon and reader for everyone . 2nd edition, Books on Demand, Norderstedt 2008, ISBN 978-3-8334-2522-6 , pp. 130-132.
- Typographical point in: Typolexikon.de .
- Measurement of writing , information on the Adobe website.
- Typography lexicon by Eberhard Dilba (PDF, 5.7 MB), accessed March 15, 2013, keyword: names of the font sizes, font size, typographic measurement system
- Font and typography , Schriftgrad.de.
- Williams, Jim: Type Matters! Simple tips for everyday typography. Merrell Holberton Pub Ltd, 2012.
- Donald E. Knuth, The TeXbook , Chapter 10 Dimensions, p. 58
- CSS Values and Units Module Level 3. Editor's Draft. W3C, December 19, 2014, accessed December 27, 2014 (English, CSS specification: absolute length measurements).
- Point density , Wikibook digital imaging methods, chapter rendering
- after Forssmann / de Jong: detailed typography (with millimeters, without Dutch)