In hot metal typesetting, a matrix (often abbreviated to "mat") is a mold for casting a letter, known as a sort, used in letterpress printing.
In letterpress typography the matrix of one letter is inserted into the bottom of a hand mould, the mould is locked and molten type metal is poured into a straight-sided vertical cavity above the matrix. When the metal has cooled and solidified the mould is unlocked and the newly-cast metal sort is removed, ready for composition with other sorts. The matrix can then be reused to produce more copies of the sort.
In continuous casting and composition casting typography, the mats for a complete font are loaded into a matrix-case and inserted into a casting machine, which casts the required sorts for a page composition automatically.
Famous quotes containing the word matrix:
“As all historians know, the past is a great darkness, and filled with echoes. Voices may reach us from it; but what they say to us is imbued with the obscurity of the matrix out of which they come; and try as we may, we cannot always decipher them precisely in the clearer light of our day.”
—Margaret Atwood (b. 1939)