Line perforation - process by which a sheet of stamps is perforated one row at a time, proceeding in one direction, over the entire sheet. The sheet is then turned ninety degrees, and the process is repeated. The distinguishing characteristic is that the holes in the vertical and horizontal rows do not coincide at the four corners of each stamp.
Lithography - a printing process in which the design is drawn, photographed, and transferred to the stone or plates of zinc or aluminum in a greasy ink. It is then fixed by treatment with acid. In printing, the stone or plate is wet with a fluid that repels the printing ink, except on the greasy lines of the design. Such printing from a smooth surface produces no pressure through the paper or raised ink as results from typography engraving.
Lottery stamp - a stamp whose fee covered postage and credit to the U.N. refugee fund; each stamp also had serial number for participation in late-year lottery. Associated with Norway and marked "June 1, 1964."