What is \kern
instruction good for and how is it defined?
I cannot find it in Knuth's book TeXbook.
[Tex/LaTex] what is \kern good for
kerningprimitives
kerningprimitives
What is \kern
instruction good for and how is it defined?
I cannot find it in Knuth's book TeXbook.
Best Answer
A "kern" is a typographic term for a nonbreakable space between two items. These items are usually, but not exclusively, glyphs.
\kern
is a TeX primitive that serves to insert nonbreakable space. E.g.,a\kern3pt b
inserts3pt
of nonbreakable space betweena
andb
.\kern
may occur in either horizontal mode (to insert horizontal space) or vertical mode (to insert vertical space). Something that\kern
can do but which is not feasible in traditional, i.e., metal-based, typography is to set a negative kerning amount. E.g.,\kern-1em
deletes rather than inserts 1em of space.That's quite puzzling. The TeXbook's index states that
\kern
occurs on pp. 10, 40, 66, 75, 87, 168, 256, 263, 280, 306, 389, 395-395, 416, 424, and 454-455. In addition, according to the book's index, the word "kerns" occurs on pp. 4, 66, 75, 95-97, 110, 157, 168, 280, 286, 306, 444, and 454-455.