I never knew to actual name of it.
Old copy machine with purple ink.
Mimeographs along with spirit duplicators and hectographs were a common technology in printing small quantities as in office work classroom.
Ditto machines made the purple copies that faded over time faster with exposure to light.
The tray was only 1 4 deep.
The stencil was thin rubber backed with paper and it was critical to get this on right while peeling the paper backing.
It didn t use a drum.
I guess we changed those.
The master for the ditto was only good for a limited number of copies as the solvent spirit dissolved.
Both pieces of paper are stained with purple ink because they went through a machine invented in 1923 called a ditto machine or spirit duplicator.
When the gelatin got too saturated with ink dad would liquidize it by heating it and re pour it into the pan les newcomer reports that the heyer hectograph co.
The duplicator that produces purple copies is not a mimeograph.
Sold a hectograph kit as late as 1974 tray gelatin a few sheets of purple inked paper and that thick cover.
The mimeograph process should not be confused with the spirit duplicator process.
Ideally each ink color would have its own screen.
Ditto machine purple print and that smell.
The ink came in tubes.
We just cleaned it out to change color.
Who could forget the purple ink that rubbed off on your hands the copies had a smell that was recognised by any 1960 70 s school kid.
The stencil duplicator or mimeograph machine often abbreviated to mimeo is a low cost duplicating machine that works by forcing ink through a stencil onto paper.
There were two cylinders with a silkscreen belt running on them.
Stencil duplication was a low cost printing method that worked by forcing ink through waxed paper stencils on to target paper.
They have now been replaced by digital duplicators scanners laser printers and photocopiers but for many years they were the primary means of reproducing documents for limited run distribution the duplicator was pioneered by thomas edison and david gestetner with gestetner dominating the market up until.