Spirit Duplicator, or direct fluid duplicator, is a form of hectography that evolved from the gelatin hectograph (see image to the right), which uses a gelatin pad. A spirit duplicator is called a fluid hectograph because it uses spirits, or alcohol, to make its duplications. The maximum practical number of copies is 500 with the maximum size of 11 in x 17 in. (Doss 2). "The usual run on these machines is up to 300 copies, but may vary according to the amount of solvent used and the transfer capacity of the master" (Fisher 34).
The spirit duplicator was an improvement to the gelatin hectograph process: "the gelatin pad was replaced by a waxed- paper master sheet, and the liquid ink was replaed by a form of carbon paper, which made distinctively purple impressions "on the master" (Owen 47).
Process of Duplication
"The fluid process of hectography is employed when up to about 500 copes are needed. In this process the master is prepared in reverse by placing the hectograph carbon face up on the back of the master. To make copies, the master is placed on the drum or cylinder with the inked side up. Rotation of the drum causes a sheet of paper to be moistened with alcoholl it is the pressed against the master, thus transferring a small amount of the dye to the paper" (Doss 17).
Unlike the gelatin hectograph, the "fluid or "spirit" process of duplicating omits use of the gelatin blanket. Copy is typed with the hectograph carbon sheet behind the master, and the aniline dye- treated carbon appears in mirror image on the reverse side of the master. This master is placed on a drum of the rotary duplicating machine. The blank copy paper is slightly moistened by spirit solvent as it is fed through the machine and picks up enough of the aniline dye as it presses against the revolving master to form a sharp image of the typed characters." (Fisher 33-34).
"In principle spirit duplicating (or hectography) is a process whereby the text is typed or written with the aid of an alcohol soluble dye-carbon which is transferred to the paper in a number of copies" (Gardiner 77). In order to duplicate documents, it was necessary to first copy them onto the appropriate spirit master.
"A master is any original from which copies may be physically duplicated" (Fisher 33). "Masters should be made on hectograph master paper, and copies should be made on hectograph paper stock to get the best results" (Doss 16). Masters can be made by typing, printing, writing, drawing, or stamping" (Fisher 33).
The spirit duplicator is essentially divided into three types:
- hand operated portable machines
- electrically operated machines
- electrically operated systems or line selecting machines
Ditto: The trademark name of a line of hectographic duplicators and supplies manufactured by Ditto, Inc." (Doss 29).
The spirit duplicator is sometimes referred to as a Ditto machine because for "rotary spriti duplicators, the best known of which were produced by the Ditto Co." (Owen 47).
"The "spirit" in that name refers to methyl alcohol, a small amount of which was applied to each sheet of copy paper as it entered the machine, dampening it just enough to dissolve a bit of the waxy purple ink from the master, which was attached to a rotating drum" (Owen). The spirit was used because "instead of water to dissolve a small part of the ink, a special "spirit" solvent is used to accomplish the transfer of an aniline dye" (Fisher 33).
"Duplicating fluids often contain very high menthanol concentrations. Given the lack of sufficient ventilation typically found in schools, spirit duplicator use can be a significant source of indoor air pollution. Because of the toxicity of methanol, it is of value to asses the extent of exposure among school workers" (Susi).
One author commented that "The alcohol gave the copies a characteristically terrible smell, adored by schoolchildren of my generation" (Owen 47).
Notion of Spirit
The spirit is the essence of the duplication process.
Most copies were typically purple. Although for the gelatin process "At least eight colors are available but purple is generally used because of its density and contrast" (Doss 15), the direct fluid method had less options since "dye colors may be red, blue, green, black or purple; longest runs are generally achieved by using the purple" (Fisher 34). There is possibility for multicolored copies: "all five colors may be reproduced on the same run, since different carbons may be used for different parts of the master" (Fisher 34).
"In general, [the spirit duplicator] produces a darker copy than the [gelatin hectograph] because the moistened fibers of the paper are dyed by the transfer of the ink in the fluid process, whereas in the gelatin process the dye is deposited on the surface of the paper. This factor increases the legibility and permanence of the reproduced material when the fluid process is used" (Fisher 34).
The spirit duplicator was typical equipment in offices and schools. "Spirit duplicators are commonly used by teachers and teaching assistants for school copying needs" (Susi). Spirit duplicated copies were used in universities as well. At King's College, Cambridge "David Wilcock's famous carol arrangements first made their appearance on purple spirit- duplicator sheets in 1959" (Harper).
The This copying processing was less troublesome to complete than the spirit duplicator because it did not need an extra step to create a spirit master.
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- Doss, Milburn P. (Ed). Information Processing Equipment. New York: Reinhold Publishing Corporation, 1955.
- Fisher, Harrison M. Today's Business Machines. Chicago: American Technical Society, 1959
- Gardiner, A. W. Typewriting and Office Duplicating Processes. New York: Focal Press, 1968.
- Owen, David. Copies in seconds : how a lone inventor and an unknown company created the biggest communication breakthrough since Gutenberg: Chester Carlson and the birth of the Xerox machine. New York: Simon & Schuster, 2004.
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- Schwartz, Hillel. The Culture of the Copy: Striking Likenesses, Unreasonable Facsimiles. New York: Zone Books, 1996.