Printing Plate

Printing Plate, surface from which printing is done. Three configurations are possible. Relief plates have raised image areas to which ink is applied by rollers and then transferred either directly or indirectly (offset) to paper or other material. Hard metal or plastic relief plates are used in the letterpress process; soft rubber or plastic, in the flexographic process. Planographic plates have image areas on the same plane as the nonimage areas and therefore require that the nonimage areas be treated to repel ink. Intaglio plates have image areas recessed below the nonimage areas. Ink is applied to the entire plate and then wiped from the smooth nonimage surface with a steel blade. The ink remaining in the recesses is transferred to the paper during printing. See also Lithography; Photoengraving; Printing Techniques.