Ligature (writing)
In writing and typography, a ligature occurs where two or more graphemes or letters are joined to form a single glyph. Examples are the characters and used in English and French, in which the letters and are joined for the first ligature and the letters and are joined for the second ligature. For stylistic and legibility reasons, and are often merged to create ; the same is true of and to create. The common ampersand,, developed from a ligature in which the handwritten Latin letters and were combined.
History
The earliest known script Sumerian cuneiform and Egyptian hieratic both include many cases of character combinations that gradually evolve from ligatures into separately recognizable characters. Other notable ligatures, such as the Brahmic abugidas and the Germanic bind rune, figure prominently throughout ancient manuscripts. These new glyphs emerge alongside the proliferation of writing with a stylus, whether on paper or clay, and often for a practical reason: faster handwriting. Merchants especially needed a way to speed up the process of written communication and found that conjoining letters and abbreviating words for lay use was more convenient for record keeping and transaction than the bulky long forms.File:Broken l.svg|thumb|class=skin-invert-image|Doubles during the Roman Republic era were written as a sicilicus. During the medieval era several conventions existed. However, in Nordic texts a particular type of ligature appeared for ll and tt, referred to as "broken l" and "broken t".
Around the 9th and 10th centuries, monasteries became a fountainhead for these types of script modifications. Medieval scribes who wrote in Latin increased their writing speed by combining characters and by introducing notational abbreviations. Others conjoined letters for aesthetic purposes. For example, in blackletter, letters with right-facing bowls and those with left-facing bowls were written with the facing edges of the bowls superimposed. In many script forms, characters such as,, and had their vertical strokes superimposed. Scribes also used notational abbreviations to avoid having to write a whole character in one stroke. Manuscripts in the fourteenth century employed hundreds of such abbreviations.
In handwriting, a ligature is made by joining two or more characters in an atypical fashion by merging their parts, or by writing one above or inside the other. In printing, a ligature is a group of characters that is typeset as a unit, so the characters do not have to be joined. For example, in some cases the ligature prints the letters and with a greater separation than when they are typeset as separate letters. When printing with movable type was invented around 1450, typefaces included many ligatures and additional letters, as they were based on handwriting. Ligatures made printing with movable type easier because one sort would replace frequent combinations of letters and also allowed more complex and interesting character designs which would otherwise collide with one another.
Because of their complexity, ligatures began to fall out of use in the 20th century. Sans serif typefaces, increasingly used for body text, generally avoid ligatures, though notable exceptions include Gill Sans and Futura. Inexpensive phototypesetting machines in the 1970s also generally avoid them. A few, however, became characters in their own right, see below the sections about [|German ß], [|various Latin accented letters], & et al.
The trend against digraph use was further strengthened by the desktop publishing revolution. Early computer software in particular had no way to allow for ligature substitution, while most new digital typefaces did not include ligatures. As most of the early PC development was designed for the English language dependence on ligatures did not carry over to digital. Ligature use fell as the number of traditional hand compositors and hot metal typesetting machine operators dropped because of the mass production of the IBM Selectric brand of electric typewriter in 1961. A designer active in the period commented: "some of the world's greatest typefaces were quickly becoming some of the world's worst fonts."
Ligatures have grown in popularity in the 21st century because of an increasing interest in creating typesetting systems that evoke arcane designs and classical scripts. One of the first computer typesetting programs to take advantage of computer-driven typesetting was Donald Knuth's TeX program. Now the standard method of mathematical typesetting, its default fonts are explicitly based on nineteenth-century styles. Many new fonts feature extensive ligature sets; these include FF Scala, Seria and others by Martin Majoor and Hoefler Text by Jonathan Hoefler. Mrs Eaves by Zuzana Licko contains a particularly large set to allow designers to create dramatic display text with a feel of antiquity.
A parallel use of ligatures is seen in the creation of script fonts that join letterforms to simulate handwriting effectively. This trend is caused in part by the increased support for other languages and alphabets in modern computing, many of which use ligatures somewhat extensively. This has caused the development of new digital typesetting techniques such as OpenType, and the incorporation of ligature support into the text display systems of macOS, Windows, and applications like Microsoft Office. An increasing modern trend is to use a "Th" ligature which reduces spacing between these letters to make it easier to read, a trait infrequent in metal type.
Today, modern font programming divides ligatures into three groups, which can be activated separately: standard, contextual and historical. Standard ligatures are needed to allow the font to display without errors such as character collision. Designers sometimes find contextual and historic ligatures desirable for creating effects or to evoke an old-fashioned print look.
Ligatures are also used for logo creation, such as the Bluetooth logo, and ).
Latin alphabet
Stylistic ligatures
Many ligatures combine with the following letter. A particularly prominent example is . The tittle of the in many typefaces collides with the hood of the when placed beside each other in a word, and are combined into a single glyph with the tittle absorbed into the. Other ligatures with the letter f include, , , , and . In Linotype, ligature matrices for,,,,,,,,,, and for followed by a full stop, comma, or hyphen are optional in many typefaces, as well as the equivalent set for the doubled, as a method to overcome the machine's physical restrictions.These arose because with the usual type sort for lowercase, the end of its hood is on a kern, which would be damaged by collision with raised parts of the next letter.
Ligatures crossing the morpheme boundary of a composite word are sometimes considered incorrect, especially in official German orthography as outlined in the Duden. An English example of this would be in shelfful; a German example would be Schiff. Some computer programs provide a setting to disable ligatures for German, while some users have also written macros to identify which ligatures to disable.
Turkish distinguishes dotted and dotless "I". If a ligature with f were to be used in words such as fırın and fikir , this contrast would be obscured. The ligature, at least in the form typical to other languages, is therefore not used in Turkish typography.
Remnants of the ligatures / and / from Fraktur, a family of German blackletter typefaces, originally mandatory in Fraktur but now employed only stylistically, can be seen to this day on street signs for city squares whose name contains Platz or ends in -platz. Instead, the "sz" ligature has merged into a single character, the German ß – see below.
Sometimes, ligatures for , ,,,, and are used.
Besides conventional ligatures, in the metal type era some newspapers commissioned custom condensed single sorts for the names of common long names that might appear in news headings, such as "Eisenhower", "Chamberlain". In these cases the characters did not appear combined, just more tightly spaced than if printed conventionally.