Widely referred to as the ditto machine, the spirit duplicator
was essentially an early printer invented in 1923 by Wilhelm
Ritzerfeld. Its name "spirit duplicator" refers to the alcohols
or “spirits” which were used as inks.

They were mainly used in organizations like schools, churches,
and various clubs. Basically, any place that often needed to
produce learning materials, newsletters, brochures, and event
flyers. Because hey had the ability to print multiple colors in a
single pass, they became very popular with cartoonists.

Initially, the fluid consisted of a 50/50 mix of isopropanol and
methanol. In 1938 a nonflammable solvent came out and had
a pleasant odor. It was 10% of monofluoro tri-chloro methane
and 90% of a mixture of 50% methyl alcohol, 40% ethyl alcohol,
5% water and 5% of ethylene glycol mono-ethyl ether. 

Sarah Norman