upright 2.0, alt=A diagram showing the line terms used in typography
In
typography
Typography is the art and technique of arranging type to make written language legible, readable and appealing when displayed. The arrangement of type involves selecting typefaces, point sizes, line lengths, line-spacing ( leading), and ...
, the x-height, or corpus size, is the distance between the
baseline and the
mean line
In typography, the mean line is the imaginary line at the top of the x-height.
upright 2.0, alt=A diagram showing the line terms used in typography
Round glyphs will tend to break ( overshoot) the mean line slightly in many typefaces, since th ...
of lowercase letters in a
typeface
A typeface (or font family) is the design of lettering that can include variations in size, weight (e.g. bold), slope (e.g. italic), width (e.g. condensed), and so on. Each of these variations of the typeface is a font.
There are list of type ...
. Typically, this is the height of the letter ''x'' in the font (the source of the term), as well as the letters ''v'', ''w'', and ''z''. (Curved letters such as ''a'', ''c'', ''e'', ''m'', ''n'', ''o'', ''r'', ''s'', and ''u'' tend to exceed the x-height slightly, due to
overshoot; ''i'' has a dot that tends to go above x-height.) One of the most important
dimensions of a font, x-height defines how high lowercase letters without
ascenders are compared to the
cap height
In typography, cap height is the height of a capital letter above the baseline for a particular typeface.http://pfaedit.sourceforge.net/glossary.html Glossary of (some) Typographic Terms It specifically is the height of capital letters that are f ...
of uppercase letters.
Display typeface
A display typeface is a typeface that is intended for use at large sizes for headings, rather than for extended passages of body text.
Display typefaces will often have more eccentric and variable designs than the simple, relatively restrained ...
s intended to be used at large sizes, such as on signs and posters, vary in x-height. Many have high x-heights to be read clearly from a distance. This, though, is not universal: some display typefaces such as
Cochin
Kochi (), also known as Cochin ( ) ( the official name until 1996) is a major port city on the Malabar Coast of India bordering the Laccadive Sea, which is a part of the Arabian Sea. It is part of the district of Ernakulam in the state of K ...
and
Koch-Antiqua
Koch-Antiqua is a serif typeface intended for decorative and display use, designed by Rudolf Koch and published by the Klingspor Type Foundry from 1922 onwards. It is a delicate face with a low x-height, intended for decorative printing rather tha ...
intended for publicity uses have low x-heights, to give them a more elegant, delicate appearance, a mannerism that was particularly common in the early twentieth century.
Many sans-serif designs that are intended for display text have high x-heights, such as
Helvetica
Helvetica (originally Neue Haas Grotesk) is a widely used sans-serif typeface developed in 1957 by Swiss typeface designer Max Miedinger and Eduard Hoffmann.
Helvetica is a neo-grotesque design, one influenced by the famous 19th century (1890s) ...
or, more extremely,
Impact
Impact may refer to:
* Impact (mechanics), a high force or shock (mechanics) over a short time period
* Impact, Texas, a town in Taylor County, Texas, US
Science and technology
* Impact crater, a meteor crater caused by an impact event
* Impact ...
.
Design considerations
Medium x-heights are found on fonts intended for body text, allowing more balance and contrast between upper- and
lowercase
Letter case is the distinction between the Letter (alphabet), letters that are in larger uppercase or capitals (or more formally ''majuscule'') and smaller lowercase (or more formally ''minuscule'') in the written representation of certain lang ...
letters and a brighter page. They then increase again for
optical sizes of fonts designed for small print, such as captions, so that they can be clearly read printed small.
![General x-height sample image](https://upload.wikimedia.org/wikipedia/commons/1/15/General_x-height_sample_image.png)
High x-heights on display typefaces were particularly common in designs in the 1960s and '70s, when
International Typeface Corporation
The International Typeface Corporation (ITC) was a type manufacturer founded in New York in 1970 by Aaron Burns, Herb Lubalin and Edward Rondthaler. The company was one of the world's first type foundries to have no history in the production of me ...
released popular variations of older designs with boosted x-heights; notable examples of this trend include
Avant Garde Gothic
ITC Avant Garde Gothic is a geometric sans serif font family based on the logo font used in the ''Avant Garde'' magazine. Herb Lubalin devised the logo concept and its companion headline typeface, and then he and Tom Carnase, a partner in Lubalin' ...
and
ITC Garamond
Garamond is a group of many serif typefaces, named for sixteenth-century Parisian engraver Claude Garamond, generally spelled as Garamont in his lifetime. Garamond-style typefaces are popular and particularly often used for book printing and bo ...
. More recently, some typefaces such as
Mrs Eaves
Mrs Eaves is a transitional serif typeface designed by Zuzana Licko in 1996. It is a variant of Baskerville, which was designed in Birmingham, England, in the 1750s. Mrs Eaves adapts Baskerville for use in display contexts, such as headings and b ...
,
Neutraface
Neutraface is a geometric sans-serif typeface designed by Christian Schwartz for House Industries, an American digital type foundry. It was influenced by the work of architect Richard Neutra and was developed with the assistance of Neutra's so ...
and
Brandon Grotesque
Brandon Grotesque is a sans-serif typeface designed by Hannes von Döhren of HVD Fonts during 2009 and 2010. Spacing and kerning was done by Igino Marini of iKern. The typeface includes Thin, Light, Regular, Medium, Bold and Black weights. Italic ...
have been issued with distinctively low x-heights to try to create a more elegant appearance. While computers allow fonts to be printed at any size, professional font designers such as Adobe issue fonts in a range of optical sizes optimized to be printed at different sizes. As an example of this, Mrs Eaves exists in two versions: an original style intended to give an elegant, bright appearance, and a less distinctive 'XL' design intended for body text.
Some research has suggested that while higher x-heights may help with reading smaller text, a very high x-height may be counterproductive, possibly because it becomes harder to identify the shape of a word if every letter is nearly the same height. For the same reason, some sign manuals discourage all-capitals text.
Use in web design
In
computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, e ...
one use of x-height is as a unit of measurement in
web pages. In
CSS
Cascading Style Sheets (CSS) is a style sheet language used for describing the presentation of a document written in a markup language such as HTML or XML (including XML dialects such as SVG, MathML or XHTML). CSS is a cornerstone techno ...
and
LaTeX
Latex is an emulsion (stable dispersion) of polymer microparticles in water. Latexes are found in nature, but synthetic latexes are common as well.
In nature, latex is found as a milky fluid found in 10% of all flowering plants (angiosperms ...
the x-height is called an ex. The use of ex in dimensioning objects, however, is less stable than use of the
em across
browsers.
Internet Explorer
Internet Explorer (formerly Microsoft Internet Explorer and Windows Internet Explorer, commonly abbreviated IE or MSIE) is a series of graphical user interface, graphical web browsers developed by Microsoft which was used in the Microsoft Wind ...
, for example, dimensions ex at exactly one half of em, whereas
Mozilla Firefox
Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. It uses the Gecko rendering engine to display web pages, which implements current and a ...
dimensions ex closer to the actual x-height of the
font
In metal typesetting, a font is a particular size, weight and style of a typeface. Each font is a matched set of type, with a piece (a "sort") for each glyph. A typeface consists of a range of such fonts that shared an overall design.
In mod ...
, rounded relative to the font's current
pixel
In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device.
In most digital display devices, pixels are the smal ...
height. Thus, the exact ratio of ex to em can vary by font size within a browser if the determined values are rounded to the nearest whole unit. For example, a browser calculating an x-height of 45% on a font 10 pixels tall may round ex to either 4 pixels or 5 pixels or leave it at 4.5 pixels.
Other important dimensions
Lowercase letters whose height is greater than the x-height either have
descender
In typography and handwriting, a descender is the portion of a letter that extends below the baseline of a font.
For example, in the letter ''y'', the descender is the "tail", or that portion of the diagonal line which lies below the ''v'' c ...
s which extend below the
baseline, such as ''y'', ''g'', ''q'', and ''p'', or have
ascenders which extend above the x-height, such as ''l'', ''k'', ''b'', and ''d''. The ratio of the x-height to the
body height is one of the major characteristics that defines the appearance of a typeface. The height of the capital letters is referred to as
cap height
In typography, cap height is the height of a capital letter above the baseline for a particular typeface.http://pfaedit.sourceforge.net/glossary.html Glossary of (some) Typographic Terms It specifically is the height of capital letters that are f ...
. x-height is most important in regular designs, such as most serif and sans-serif designs;
script typeface
Script typefaces are based upon the varied and often fluid stroke created by handwriting. They are generally used for display or trade printing, rather than for extended body text in the Latin alphabet. Some Greek alphabet typefaces, especially h ...
s that mimic irregular handwriting and calligraphy may not have a consistent x-height across all letters.
See also
*
En (typography)
An en (from English '' en quadrat'') is a typographic unit, half of the width of an em. By definition, it is equivalent to half of the body height of the typeface (e.g., in 16-point type it is 8 points). As its name suggests, it is also tradi ...
*
Small caps
In typography, small caps (short for "small capitals") are characters typeset with glyphs that resemble uppercase letters (capitals) but reduced in height and weight close to the surrounding lowercase letters or text figures. This is technicall ...
References
External links
Definition of x-height at typophile.com
{{DEFAULTSORT:X-Height
Typography