Compositors or phototypesetters operate and tend machines that provide typeset matter. Typeset matter is used to prepare printing plates for the pressroom worker who prints newspapers, magazines and various other publications.
Compositors read from copy clipped to typesetting machines and operate a keyboard. There are two kinds of compositors:
Linotype compositors: assemble letters into lines of words, called slugs.
Monotype compositors: feed perforated tape into machines that read and select metal moulds for each letter.
Phototypesetters type text and produces a magnetic or perforated tape. The tape is fed into a computer that hyphenates, creates columns, and makes a second tape, which is photographed.