COPYGRAPH

Etymology

Noun

copygraph (plural copygraphs)

(dated) An early means of producing multiple copies of a document by means of pressing it against a slab of gelatin softened with glycerin and making further copies from the resulting reversed image.

Source: Wiktionary

Cop"y*graph, n.

Definition: A contrivance for producing manifold copies of a writing or drawing.

Note: The writing or drawing is made with aniline ink on paper, and a reverse copy transferred by pressure to a slab of gelatin softened with glycerin. A large number of transcripts can be taken while the ink is fresh. Various names have been given to the process [the gelatin copying process], some of them acceptable and others absurd; hectograph, polygraph, copygraph, lithogram, etc. Knight.

Source: Webster’s Unabridged Dictionary 1913 Edition