Mimeograph machine

The mimeograph machine (commonly abbreviated to mimeo) or stencil duplicator was a printing machine that was far cheaper per copy than any other process in runs of several hundred to several thousand copies. It was not capable of photocopying a document, as a special stencil had to be prepared by hand. Popular until the early 1990s in the preparation of tests and notes for use in classrooms, and especially in science fiction fandom, it has since been largely supplanted in the First World by photocopying and offset printing.

While photocopying became a less expensive and more efficient duplicating option in schoolrooms in the 1990's, it was clearly no substitute for the rapture felt by countless thousands of school children as they brought a fresh-off-the-mimeo quiz or handout to their noses and savored the somewhat sweet, but otherwise impossible to describe, scent and felt the damp and cool paper on their faces.

The stencil proper was made of waxed mulberry paper. This rather floppy waxed sheet was backed by tissue or carbon paper and a sheet of stiff card, the sheets being bound together at the top. This assemblage placed in a typewriter to create the original. The typewriter ribbon action had to be disabled so that the bare, sharp type element struck the stencil. The impact of the typewriter key displaced the wax, making the tissue paper permeable to the oil-based ink. If the striking surface of the letters on the typewriter became clogged with wax, the letter forms would close up, turning letters like "o" or "b" into solid black blobs. If carbon paper was used behind the stencil, it would generate a proof copy on the card backing. Alternately, proof could be read by placing the stencil on a light table.

A variety of specialized styli could be used on the stencil to render lettering or illustrations by hand against a toothy plastic backing card. On-stencil illustration was an art. Mistakes could be corrected by brushing them out with "correction fluid" and retyping once it had dried. This substance was known as "corflu" in the United States and "obliterine" in Australia and the UK.

The stencil was wrapped around the drum of the (manual or electrical) machine which was filled with ink. When a blank sheet of paper was drawn between the rotating drum and a pressure roller, ink was forced out through the marks on the stencil. True mimeo paper was softer and a bit shaggier than standard bond paper. The ink was most often black, although green, red, blue, brown, and purple inks were available. The purple ink tended to halo after printing. If one put the stencil on the drum wrong-side-out, one's copies came out mirror-imaged. The process could be messy for inexperienced users. In addition the striking surface of the letters on the typewriter would quickly become clogged with wax; the closed letter forms, such as "o" or "b" making a stencil cut that resulted in black blobs instead of white space in the center.

Another device called an electrostencil machine could make mimeo stencils from an already-printed original. It worked by scanning the original on a rotating drum with a moving optical head, and burning through the blank stencil with an electric spark in the places where the optical head detected ink. It was slow and filled the air with ozone and other pollutants, and text produced from electrostencils was of lower resolution than that produced by typed stencils, though the process was good for reproducing illustrations. A skilled mimeo operator using an electrostencil and a very coarse half-tone screen could make acceptable printed copies of a photograph. This took considerable care both in preparing the stencil and in maintaining evenness of the ink flow during printing. During the declining years of the mimeograph, some people made stencils with computers and dot-matrix impact printers.

Gestetner, Risograph, and other companies still make and sell highly automated mimeograph-like machines externally similar to photocopiers, as the mimeo process is faster and less expensive than xerography for moderate to large print runs, although the image quality is inferior. The modern version of a mimeograph is called a digital duplicator or copyprinter and contains a scanner, a thermal head for stencil cutting, and a large roll of stencil material entirely inside the unit, making the stencils and mounting and unmounting them from the print drum automatically, making it almost as easy to operate as a photocopier. Risographs are the best known of these machines.

Mimeography proper continues to be a working technology in the Third World.

Origins of the Mimeograph

Thomas Edison received US patent 180,857 for "Autographic Printing" on August 8, 1876. The patent covered the electric pen, used for making the stencil, and the flatbed duplicating press. In 1880 Edison obtained a further patent, US 224,665: "Method of Preparing Autographic Stencils for Printing", which covered the making of stencils using a file plate, a grooved metal plate on which the stencil was placed which perforated the stencil when written on with a blunt metal stylus. Edison did not coin the word "mimeograph", which was first used by Albert Blake Dick when he licensed Edison's patents in 1887.

Dick received a Trademark Registration for the term "Mimeograph", [TM registered in US Patent Office as # 0356815, Currently listed as a DEAD entry, but listing the AB Dick Co of Chicago IL as the owner of the name.

Others who worked concurrently on the development of stencil duplicating were Eugenio de Zaccato and David Gestetner, both in Britain.

The term "Mimeograph" was originally protected as a trademark, however over time the term became generic and is now an example of a genericized trademark ^*. "Roneograph" (also "Roneo machine") was another trademark used for mimeograph machines.

Mimeographs were used extensively in the production of fanzines in the middle 20th century, before photocopiers became widespread. In sufficient quantities, however, they are still more economical.

Certain typographical practices were peculiar to mimeographical publication, due to the tendency of the stencil to tear, thus becoming useless. Underlining was neither used in spaces nor on the letters with descenders. The expression of irony by crossing out letters was done with a forward slash, not a hyphen. This differs from the method in hypertext.

Penelope Rosemont pioneered a surrealist technique of peeling the backing away from the stencil to create a "mimeogram".

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Origins of the Mimeograph

See also