The mimeograph machine (commonly abbreviated to mimeo) or stencil duplicator is a largely obsolete printing machine that once held sway in businesses as cheaper per copy than commercial printing for small runs of several dozen to several thousand copies.

Stencil duplicators, spirit duplicators and hectographs were for many decades used to print short-run office work, classroom materials and church bulletins. These technologies began to be supplanted by photocopying in the 1960s. Although photocopying and cheap offset printing have replaced mimeography almost entirely in the First World, mimeography continues to be a working technology in the Third World as no electricity is required. In mid-range quantities, it is still more economical.

The mimeography process

The image transfer medium is waxed mulberry paper. This flexible waxed sheet is backed by a sheet of stiff card stock, with the sheets bound at the top. This "stencil" assemblage is placed in a typewriter to create the original, although the typewriter ribbon has to be disabled so that the bare, sharp type element strikes the stencil directly. The impact of the type element displaces the wax, making the tissue paper permeable to the oil-based ink. This is called "cutting a stencil."

If the typewriter keys are struck too hard, letters such as "o" or "b" will be cut out, causing solid black blobs instead of loops with white space in the center. If carbon paper is used behind the stencil, it will generate a proof copy on the card backing. Such a proof can be read by placing the stencil on a light table.

A variety of specialized styli can be used on the stencil to render lettering or illustrations by hand against a toothy plastic backing card. On-stencil illustration is an art. Mistakes can be corrected by brushing them out with correction fluid and retyping once it has dried. ("Obliterine" was a popular brand of correction fluid in Australia and the United Kingdom.)

Generally, stencils are made in one of four ways. The first, the electronic stencil, is made using an electronic scanning device better known as an electronic stencil cutter. A second type is made using a thermal process, which is an infrared, one-step duplication method similar to that used on modern copiers. The third is die impressing, which is done by making pressed stencils manufactured for such use. The fourth is a stylus stencil, which uses mechanical pressure such as that exerted by a typewriter or similar device and is the type generally used to make a Mimeograph master (no electricity required).

The stencil is wrapped around the drum of the (manual or electrical) machine, which is filled with ink. When a blank sheet of paper is drawn between the rotating drum and a pressure roller, ink is forced through the marks on the stencil. True mimeo paper is softer and a bit shaggier than standard bond paper. The ink is most often black, although green, red, blue, brown, and purple inks are available (the purple ink tends to halo after printing). A little caution is required for this process since placing the stencil on the drum wrong-side-out will produce a negative or mirror-image. The process can be messy for inexperienced users.

Another device, called an electrostencil machine, sometimes was used to 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. However, 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, although the process was good for reproducing illustrations. A skilled mimeo operator using an electrostencil and a very coarse halftone screen could make acceptable printed copies of a photograph, although this took considerable care both in preparing the stencil and in maintaining evenness of ink flow during printing. During the declining years of the Mimeograph, some people made stencils with early computers and dot-matrix impact printers.

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

Origins of the Mimeograph

Thomas Edison received US patent 180,857 for "Autographic Printing" on August 8, 1876.^[1] 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.^[2]

Edison did not coin the word "mimeograph", which was first used by Albert Blake Dick^[3] when he licensed Edison's patents in 1887.^[4]

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 A. B. Dick Company of Chicago as the owner of the name. Over time, the term became generic and is now an example of a genericized trademark.^[5] ("Roneograph," also "Roneo machine," was another trademark used for mimeograph machines, although they usually were spirit/alcohol duplicators, the name coming from Spanish for rum.)

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

In 1891 Gestetner patented his Automatic Cyclostyle. This was one of the first rotary machines that retained the flatbed, which passed back and forth under inked rollers. This invention provided for more automated, faster reproductions since the pages were produced and moved by rollers instead of pressing one single sheet at a time.

By 1900 two primary types of Mimeographs had come into use: a single-drum machine and a dual drum machine. The single-drum machine uses a single drum for ink transfer to the stencil and the dual-drum machine uses two drum and silk-screens to transfer the ink to the stencils. While each type offers certain benefits that the other does not, both machines work equally well and at approximately the same speed and quality; it is a matter of preference or availability.

The Mimeograph machine was made so popular because it had the ability to make many copies cheaply. Mimeography was much cheaper than traditional print because there was no type setting, printing equipment, or intensive and skilled labor involved. One individual with a typewriter and the necessary equipment essentially became his own printing factory. This allowed for cheap mass production in an era when mass production was becoming an essential factor of society. Now instead of costly handbills or time consuming hand written copies, a mimeograph machine could rapidly produce many copies, which allowed for greater circulation of printed material and a wider usage of that material due to sheer number. Essentially, the Mimeograph became the first individual mass-distribution device.

The Mimeograph slowly evolved from a simple, personal-use, more-rapid printing device by incorporating the technological advances that came during the twentieth century. Mimeographs were outfitted from semiautomatic inking to becoming fully automatic inking relieving the need to have an individual continually ink the device. Automatic paper feeding apparatuses were added to the machines giving them the ability to feed sheets through the Mimeograph by itself. As technology progressed, Mimeographs were adapted to be able to print in multiple colors.

The smell

Bill Bryson in his memoir The Life and Times of the Thunderbolt Kid, writes "Of all the tragic losses since the 1960s, mimeograph paper may be the greatest. With its rapturously fragrant, sweetly aromatic pale blue ink, mimeograph paper was literally intoxicating. Two deep drafts of a freshly run-off mimeograph worksheet and I would be the education system’s willing slave for up to seven hours."^[6]

It is likely, however, that the author is confusing the product of the Mimeograph process with that of the spirit duplicator (also called the Ditto machine after the most prominent manufacturer of the device in the United States) which, when fresh, gives off the fragrant odor of the alcohol mixture used to transfer pigment from the master to the copies. Unlike the fresh dittos, Mimeograph copies are not known for a particular odor.

Use in Science Fiction Fandom and Art

Mimeographs were also used for low-budget amateur publishing, especially by science fiction fans, who have now turned mainly to e-mail and the World Wide Web. They were used extensively in the production of fanzines in the middle 20th century, before photocopiers became widespread.

Fans adopted certain typographical practices, due to the tendency of the mimeo stencil to tear, thus becoming useless. Often, underlining was avoided in spaces and on the letters with descenders, and sometimes replaced by dotted line. The expression of irony by crossing out letters was typically done with a forward slash. This differs from the method in hypertext.

Letters and typographical symbols were sometimes used to create illustrations, in a precursor to ASCII art. Because changing ink color in a mimeograph could be a laborious process, involving extensively cleaning the machine or, on newer models, replacing the drum or rollers, and then running the paper through the machine a second time, some fanzine publishers experimented with techniques for painting several colors on the pad, notably Shelby Vick, who created a kind of plaid "Vicolor."^[7]

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

See also

• Duplicating machines
• List of duplicating processes
• Spirit duplicator (a.k.a. 'Ditto machine')
• Gocco

References

• Hutchison, Howard. Mimeograph: Operation Maintenance and Repair. Blue Ridge Summit: Tab Books, 1979.