The heavy, flat metal surface in a letterpress machine that forces the paper against the inked type or block. On hand presses, it is lowered vertically onto the bed. On jobbing presses, it hinges open like a clamshell to receive the paper and closes parallel to the form to make the print.
Watch your fingers when the platen closes, or you'll lose them.
The pressure of the platen must be perfectly level; operators adjust it by adding thin sheets of paper behind the tympan.
Related terms
Letterpress
A relief printing process where raised, inked surfaces are pressed directly onto paper.
Handpress
A manually operated printing machine that applies pressure to ink and paper.
Typeform
The fully assembled block of type and image plates locked together for printing.
Impression
A single print run of a publication from the same setup, or the physical pressure applied by the press.