I just got done reading a book about schools in Iowa during the Great Depression (1929-1939), and came across a comment about using a "hectograph" to make duplicate copies of things.
Of all the stuff I have in the family archives here, I don't believe any of the documents are a product of this thing.
I had never heard of this; has anyone else?
Apparently it was predecessor to the mimeograph machine?
http://en.wikipedia.org/wiki/HectographThe hectograph or gelatin duplicator or jellygraph is a printing process which involves transfer of an original, prepared with special inks, to a pan of gelatin or a gelatin pad pulled tight on a metal frame.
The special aniline dyes for making the master copy came in the form of ink or in pens, pencils, carbon paper and even typewriter ribbon. Hectograph pencils and pens are sometimes still available. Various other inks have been found usable to varying degrees in the process; master sheets for spirit duplicators have also been pressed into service. (However, these are often unusable, since the spirit duplicator uses a "mirror image" on its master sheet. For the hectograph, the mirror image is on the gelatin itself.)
After transfer of the image to the inked gelatin surface, copies are made by pressing paper against it. When a pad ceased to be useful, ink could be sponged from the top of the gelatin and the pad reused for the next master. A grey-colored, thick, absorbent paper pad was supplied to cover the gelatin surface for storage. This also removed ink from the surface, but took many hours to do so. Care needed to be taken that the gelatin surface was kept clean, and not damaged by one's fingernails during duplicating.
The gelatin process produced print runs of somewhere between 20 and 80 copies, depending upon the skill of the user and the quality of the original. At least eight different colors of hectographic ink were available at one time, but purple was the most popular because of its density and contrast.
Hectography, requiring limited technology and leaving few traces behind, has been deemed useful both in low-technology environments and in clandestine circumstances where discretion was necessary. In the earlier 20th Century, the process lent itself to small runs of school classroom test papers, church newsletters and science fiction fanzines. Prisoners-of-war at Colditz Castle during World War II used an improvised hectograph to reproduce documents for a planned escape attempt.
It has also been used, though not very extensively, as an artistic medium in printmaking. The Russian Futurists used it for book illustrations, and the German expressionist Emil Nolde made four hectographs.
Stephen King, in his book, "On Writing" talks about how he and his older brother Dave used the process to create their newspaper, "Dave's Rag."
It also was used in professional situations; in Macy's advertising department during the 1950s and 1960s, full-page newspaper ad layouts were drawn with hectograph pencils and then duplicated on a hectograph to make file copies for future reference. Before the popularization of spirit duplicators and the mimeograph, there were mechanized hectography machines which used a drum, rather than a simple flat tray of gelatin.
While the hectograph process is almost entirely obsolete for printing on paper, it's still used for making temporary tattoos on human skin. Tattoo artists use hectograph pencils to draw pictures on paper and then transfer them to the recipient's skin.
