Tympan [UPDATED]

: 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.

In the world of hand-operated letterpress and lithography, a is a critical component used to manage pressure during the printing process. tympan

: The tympan acts as a buffer and a distributor of pressure. Without it, the direct force from a scraper bar or platen might damage the paper or produce an uneven ink transfer. : It is a frame over which a

: 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. : The tympan acts as a buffer and a distributor of pressure

: 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