: It is a frame over which a taut sheet of parchment, cloth, or heavy oiled paper is stretched. This frame is hinged so it can be folded down over the paper before the final impression is made.
: Printers use the space under the tympan sheet for "packing"—adding layers of paper or board to equalize the pressure across the entire surface of the type. tympan
: In Lithography , the tympan is often lubricated with grease (like LMX Red grease ) to allow the scraper bar to slide smoothly across it under high pressure. 2. The Tympanum in Architecture Tympan For Hand Lithography - Takach Press : It is a frame over which a