In Linotype, the operator selects a magazine containing brass matrices to mold an entire font of type of the size and face specified in the copy at hand. A keyboard is manipulated (or driven by paper or magnetic computer tape) to select the matrices needed to compose each line of text, including tapered spacebands, which automatically wedge the words apart to fill each line perfectly. Each matrix is transported to an assembling unit at the mold.

The slugs produced by the machine are rectangular solids of type metal (an alloy of lead, antimony, and tin) as long as the line or column measure selected. Raised characters running along the top are a mirror-image of the desired printed line. After hot-metal casting, a distributing mechanism returns each matrix to its place in the magazine. The slug of type, air-cooled briefly, is then placed in a “stick” for insertion in the proper position into the press form being assembled or made up.