In typography, a quad (originally quadrat [1] ) was a metal spacer used in letterpress typesetting. The term was later adopted as the generic name for two common sizes of spaces in typography, regardless of the form of typesetting used. An em quad (originally m quadrat) is a space that is one em wide; as wide as the height of the font. An en quad (originally n quadrat) is a space that is one en wide: half the width of an em quad.
Both are encoded as characters in the General Punctuation code block of the Unicode character set as U+2000 EN QUAD and U+2001 EM QUAD, which are also defined to be canonically equivalent to U+2002 EN SPACE and U+2003 EM SPACE respectively. [2] [3] [4]
In 1683, in Joseph Moxon's book on the art of printing, the terms m and n quadrat are attested: [5] [6]
And as there is three Heighths or Sizes to be considered in Letters Cut to the same Body, so is there three Sizes to be considered, with respect to the Thicknesses of all these Letters, when the Punches are to be Forged: For some are m thick; by m thick is meant m Quadrat thick, which is just so thick as the Body is high: Some are n thick; that is to say, n Quadrat thick, viz. half so thick as the Body is high: And some are Space thick; that is, one quarter so thick as the Body is high; though [...] we shall call these Spaces, Thick Spaces. [lower-alpha 1]
In 1771, in the first edition of the Encyclopædia Britannica , it says: [7] [lower-alpha 2]
Quadrat, in printing, a piece of metal cast like the letters, to fill up the void spaces between words, etc. There are quadrats of different sizes, as m-quadrats, n-quadrats, etc., which are, respectively, of the dimensions of these letters.
In 1841, in William Savage's A Dictionary of the Art of Printing, the terms em and en quadrat are attested: [8]
QUADRATS. Pieces of type metal, of the depth of the body of the respective sizes to which they are cast, and lower than types, so as to leave a blank space on the paper, when printed, where they are placed: an en quadrat is half as thick as its depth; an em quadrat is equal in thickness and depth, and, being square on its surface, is the true quadrat, from quadratus, squared; a two em quadrat is twice the thickness of its depth; a three em three times; and a four em four times, as their names specify. Four ems are the largest quadrats that are cast. They are used to fill out short lines; to form white lines; and to justify letters, figures, &c., in any part of a line or page.
In 1903, in Chambers Dictionary , the term quad is attested: [9]
Quad, kwod, n. (print.) an abbreviation of quadrat.—v.t. to fill with quadrats.
[...]
Quadrat, kwod′rat, n. a piece of type-metal lower than the letters, used in spacing between words and filling out blank lines (commonly Quad)—distinguished as en(), em(
), two-em(
), and three-em(
).
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 letter-spacing (tracking), as well as adjusting the space between pairs of letters (kerning). The term typography is also applied to the style, arrangement, and appearance of the letters, numbers, and symbols created by the process. Type design is a closely related craft, sometimes considered part of typography; most typographers do not design typefaces, and some type designers do not consider themselves typographers. Typography also may be used as an ornamental and decorative device, unrelated to the communication of information.
Movable type is the system and technology of printing and typography that uses movable components to reproduce the elements of a document usually on the medium of paper.
Typographic units are the units of measurement used in typography or typesetting. Traditional typometry units are different from familiar metric units because they were established in the early days of printing. Though most printing is digital now, the old terms and units have persisted.
The hyphen‐ is a punctuation mark used to join words and to separate syllables of a single word. The use of hyphens is called hyphenation. Son-in-law is an example of a hyphenated word.
A typeface is a design of letters, numbers and other symbols, to be used in printing or for electronic display. Most typefaces include variations in size, weight, slope, width, and so on. Each of these variations of the typeface is a font.
In writing, a space is a blank area that separates words, sentences, syllables and other written or printed glyphs (characters). Conventions for spacing vary among languages, and in some languages the spacing rules are complex. Inter-word spaces ease the reader's task of identifying words, and avoid outright ambiguities such as "now here" vs. "nowhere". They also provide convenient guides for where a human or program may start new lines.
In typography, leading is the space between adjacent lines of type; the exact definition varies.
An em is a unit in the field of typography, equal to the currently specified point size. For example, one em in a 16-point typeface is 16 points. Therefore, this unit is the same for all typefaces at a given point size.
An en 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. The en is sometimes referred to as the "nut", to avoid confusion with the similar-sounding "em".
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 printing's history. Since the 18th century, the size of a point has been between 0.18 and 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 desktop publishing (DTP) point as the de facto standard. The DTP point is defined as 1⁄72 of an international inch (1/72 × 25.4 mm ≈ 0.353 mm) and, as with earlier American point sizes, is considered to be 1⁄12 of a pica.
Letter spacing, character spacing or tracking is an optically consistent typographical adjustment to the space between letters to change the visual density of a line or block of text. Letter spacing is distinct from kerning, which adjusts the spacing of particular pairs of adjacent characters such as "7." which would appear to be badly spaced if left unadjusted, and leading, the spacing between lines.
In computer programming, whitespace is any character or series of characters that represent horizontal or vertical space in typography. When rendered, a whitespace character does not correspond to a visible mark, but typically does occupy an area on a page. For example, the common whitespace symbol U+0020 SPACE represents a blank space punctuation character in text, used as a word divider in Western scripts.
Sentence spacing concerns how spaces are inserted between sentences in typeset text and is a matter of typographical convention. Since the introduction of movable-type printing in Europe, various sentence spacing conventions have been used in languages with a Latin alphabet. These include a normal word space, a single enlarged space, and two full spaces.
Didot is a group of typefaces. The word/name Didot came from the famous French printing and type producing Didot family. The classification is known as modern, or Didone.
In typography, the body height or point size refers to the height of the space in which a glyph is defined.
A California job case is a kind of type case: a compartmentalized wooden box used to store movable type used in letterpress printing. It was the most popular and accepted of the job case designs in America. The California job case took its name from the Pacific Coast location of the foundries that made the case popular.
The dash is a punctuation mark consisting of a long horizontal line. It is similar in appearance to the hyphen but is longer and sometimes higher from the baseline. The most common versions are the en dash–, generally longer than the hyphen but shorter than the minus sign; the em dash—, longer than either the en dash or the minus sign; and the horizontal bar―, whose length varies across typefaces but tends to be between those of the en and em dashes.
A quadrat, in ecology and geography, is a frame used to isolate an area for study.
The history of sentence spacing is the evolution of sentence spacing conventions from the introduction of movable type in Europe by Johannes Gutenberg to the present day.
Typeface anatomy describes the graphic elements that make up letters in a typeface.