The individual matrices are assembled in the desired order for each line of the material, and a type-high metal slug with the letters in relief is cast in one piece from these matrices.

3. Another typesetting machine which operates on the same principle as the intertype is

the linotype.

4. Corrections in linotype and intertype matter are made by resetting the complete line

in which an error occurs.

METHODS OF PRINTING '^^^

Soderstrom, Walter, Photolithographers Manual, Waltwin Company, New York City, 1937.

Lithographers National Association, Inc., New York, N. Y., "Books on Lithography" reprint from Bookbinding and Book Production.

Lithographic Technical Foundation Publications, 220 East 42nd Street, New York, N. Y.

In intaglio printing (also referred to as rotogravure, photogravure, and sheet-fed gravure) the design is etched into the surface of a copper plate or cylinder, thus producing sub-surface recesses. Ink is applied to the plate or cylinder in sufficient volume to fill the recesses following which the surface proper is wiped clean. In rotogravure, the surface is cleaned by a thin steel blade known as "doctor blade" which fits tightly against the surface of the plate as the cylinder revolves. The paper is brought into direct contact with the copper plate or cylinder by means of a rubber roller. As a result, the ink is lifted out of the recesses thereby

a**"*^.

Lantton Monotype Machine Co.. Philadelphia. Pennsylvania.

Type Set by the Monotype Machine.

1. The third kind of typesetting machine is the monotype. It casts and assembles individual letters automatically. As soon as each letter is cast, it is moved into the proper place in the line of type. When the line is completed, it is moved out on the form that holds the lines of type.