Monotype produces type in individual characters, unlike Linotype, which sets type an entire line at a time. A Monotype machine consists of a 120-key keyboard, a caster, and a replaceable matrix case divided into quadrants, each holding one complete type font.
Using shift keys, the operator can select characters from any quadrant and can mix typefaces among the four fonts without changing cases. The operator types out characters and spacing to produce a paper ribbon perforated to indicate characters and spacing. The ribbon is placed on the caster, which “reads” the perforations and automatically casts the individual characters in succession.
Like the Linotype, Monotype has been almost completely superseded by photocomposition (q.v.). Monotype was more versatile than Linotype and better suited to complicated copy, such as mathematical equations and chemical formulas. Special symbols were easily incorporated into the cases that held type fonts. Because it was slower and more expensive to operate than Linotype, it was rarely used for setting solid text copy.