Before mimeograph, before spirit printers, there was the Hectograph:

The hectograph or gelatin duplicator is a printing process which involves transferring from an original sheet prepared with special inks to a gelatin pad ... After the image is transferred to the inked gelatin surface, copies are made by pressing paper against it. When a pad had ceased to be useful, the ink could be sponged off the top of the gelatin and the pad re-used for the next master.

Featured here because some "old timers" on our board (which is meeting today) started talking about "gelatin printing", and I'd never heard of it. Wanted to see if this would jog some memories amongst the three or four over-the-hill readers we have on here. :)