Ligatur

Ligatur, from the Latin ligatura meaning bond, is a single glyph that combines two or more letters into one. In typography, ligatures serve to improve legibility and visual harmony, especially in scripts with tall ascenders or lively letterforms, or where space is limited.

Ligatures have a long history in manuscript culture. With the advent of movable type, many traditional typefaces retained ligatures to reduce collisions between letters and to create smoother word shapes. Common examples include fi, fl, ff, ffi, and ffl, which were used for both aesthetic and technical reasons.

In modern typography, ligatures are often produced automatically by fonts through typographic features. OpenType defines features such as liga (standard ligatures), dlig (discretionary ligatures), and clig (contextual ligatures) that adapt ligature use to surrounding characters. Some fonts also include historical or stylistic ligatures for specific languages or design effects.

Languages and styles vary in ligature usage. Latin-script systems commonly employ fi, fl, and other standard ligatures, while some display or blackletter fonts emphasize stylistic ligatures. In multilingual settings, ligature availability can differ across fonts and scripts, and some designers choose to disable ligatures for readability or consistency with a particular aesthetic.

Encoding and fonts: Several ligatures have dedicated Unicode code points, notably the common fi, fl, ffi, and ffl ligatures (U+FB01 through U+FB04). Other ligatures include æ (U+00E6), œ (U+0153), and the ligature IJ (U+0133). Fonts may also provide additional discretionary or contextual ligatures beyond these standards.