Mimeograph
A cheap duplicating machine that forced ink through a cut wax stencil — the copier of schools and clubs before the photocopier.
You wrote on a wax-coated stencil with a typewriter set to strike without a ribbon, or drew on it by hand; the strokes cut through the wax. The stencil wrapped around an ink-filled rotating drum, and where the wax was gone the ink pushed through and printed the character onto paper fed past it. A single stencil yielded hundreds to thousands of copies for almost nothing.
Thomas Edison held early patents on the technique in the 1870s and '80s, and A.B. Dick launched the "Mimeograph" trademark in 1887. The machine was everywhere in schools, churches and fanzine offices until xerography and the photocopier took over in the 1960s and '70s. Its purple-inked cousin was the spirit duplicator.