In the manufacture of metal type used in letterpress printing, a matrix (from the Latin meaning womb or a female breeding animal) is the mould used to cast a letter, known as a sort.[4] Matrices for printing types were made of copper.[5]
However, in printmaking the matrix is whatever is used, with ink, to hold the image that makes up the print, whether a plate in etching and engraving or a woodblock in woodcut.