Matrixing

a printing operation for the reproduction of the recessed image of line and half-tone graphic elements from the original printing plate on sheets of matrix material by pressing for series production of stereotypes. The original raised plate consists of text material set manually or on Linotype and Monotype machines, as well as zincograph plates and spacing elements, mounted in a chase frame. Heat-resistant cardboard 0.5-1.0 mm thick is used as matrix material for cast metal stereotypes; sheets of vinyl plastic or lead calibrated according to thickness (1-2 mm) are used for electrotype plates; and filtering cardboard impregnated with Bakelite and covered with a special surface are used for plastic and rubber stereotypes.

In matrixing, sheets of matrix material are laid on the original plate and covered with an elastic lining of kersey, rubberized fabric, or porous plastic. Matrices are most frequently made on hydraulic presses with various degrees of mechanization and automation. The working block, consisting of the original plate, the matrix material, and an elastic layer, is placed on the lower plate of the press, and the required pressure is generated by raising the plate or lowering the upper plate. The pressure is 1-20 meganewtons per sq m (MN/m²), or 10-20 kilograms-force per sq cm, and, for lead matrices, up to 120 MN/m².