Mimeograph, also called stencil duplicator, duplicating machine that uses a stencil consisting of a coated fibre sheet through which ink is pressed. Employing a typewriter with the ribbon shifted out of the way so that the keys do not strike it, the information to be duplicated is typed on the stencil. The keys cut the coating on the stencil and expose the fibre base, making it possible for ink to pass through it. Corrections can be made by a sealing fluid that permits retyping over the patched-error position. Signature or drawings are added on the stencil with a hand stylus.
