In metal type, any part of a character created by the typefounder to overhang (extend beyond) its allocated space on the surface of its metal block, as in the italic f. This extension is necessary to create appropriate spacing between some character pairs. In contemporary usage, a verb, indicating the selective removal or addition of small increments of space between individual character pairs (for example, to kern a pair of letters). See also kerning.
In digital and phototypesetting, the adjustment of intercharacter space to improve or otherwise alter the overall appearance of characters, words, and lines of type. As distinguished from tracking or uniform letterspacing, in which an equal amount of space is added or subtracted between a series of character pairs, kerning (or pair kerning) usually refers to the selective addition or subtraction of small, individually-determined amounts of space, depending on which is needed to improve spacing.
Kerning adjustments are usually made in units that are small divisions of the em and may be made both automatically (with kerning tables included with the font and/or supplementary kerning programs) and with individual adjustments by the compositor. When kerning is used to create an even over-all appearance of spacing between characters, both the process and the result are sometimes called optical letterspacing. See also letterspacing, unit system.
In hand-set composition with metal type, the compositor was able to subtract space between character pairs by mortising, or cutting away, pieces of the metal body of the type to achieve a better fit. To add space, the compositor inserted thin nonprinting pieces of metal (and sometimes paper) between character pairs. The term kern had a different meaning in reference to metal type. See also kern.
The action of depressing a single key on a keyboard.
Words used as reference in the design and fitting (spacing) of letterforms. A key word usually consists of letters containing the basic strokes of an alphabet: for the Latin alphabet, stems and diagonals (as in H, I, N, M) and rounded strokes (as in O, C, G), also letters made up of a combination of stems and rounds (such as P, R, B). Key words serve as a sampling of design and spacing for the typeface and are studied for the proper relationship of forms and of positive to negative space (the shapes of the letters themselves versus the shapes these letters create out of their background). HAMBURGEVONS (hamburgevons) or HAMBURGEFONSTIV (hamburgefonstiv) and CHAMPION (champion) are commonly used. Also known as test words. In the U.K., sometimes called trial words. See also proof.
The distance from the baseline to the top of the tallest lowercase ascender, sometimes the k ascender. In some typefaces the k height is taller than the H height (capital height).
The distance from the top of the tallest lowercase ascender to the bottom of the lowest descender. Traditionally, the kp height is usually 5 to 10 percent less than the size of the measured type sample. If caps are taller than ascenders, however, as in some scripts, a separate value may be used, such as the Hp or Ep height.