Thermofax

Thermo-Fax (very often Thermofax [The 3M website's "history-at-a-glance" page uses the form "Thermo-Fax^TM", and this form is seen on the nameplates of vintage machines and 3M advertisements on online auction sites. However, the vast majority of hits from non-3M sources, including newspaper searches, Google, Google Books, and Google Scholar use the forms "Thermofax," or "thermofax," with lower-case f, no hyphen, and no trademark symbol.] ) is 3M's trademarked name for a photocopying technology which it introduced in 1950. [cite web|url=http://solutions.3m.com/wps/portal/!ut/p/kcxml/04_Sj9SPykssy0xPLMnMz0vM0Q9KzYsPDdaP0I8yizeINzQw1C_IcFQEALTWaZE!|title=3M History At A Glance|year=2006|accessdate=2006-09-17|publisher=3M Corporation: "In the 1950s, 3M introduced the Thermo-Fax copying process..."] [cite web|url=http://dis.um.es/~barzana/Divulgacion/Informatica/Xerografia.html|title=50 años de Xeroxcopias|author=David M. Kiefer|publisher=professor Rafael Barzanallana - Universidad de Murcia; probably a copy of an article published elsewhere|year=2000|accessdate=2006-09-17: "The biggest seller was the Thermofax, introduced in 1950 by Minnesota Mining & Mfg. (3M). It was based on the thermographic process discovered by Carl S. Miller while he was studying for a Ph.D. in physical chemistry at the University of Minnesota in 1940."] It was a form of thermographic printing and an example of a dry silver process. [The original 1950 process did not use silver, but a few years later the original process was supplanted by an improved silver-based version.]

It was a significant advance as no chemicals were required, other than what was contained in the copy paper. A thin sheet of heat sensitive copy paper was placed on the original document to be copied, and exposed to infrared energy. Where the image on the original contained carbon, the image absorbed the infrared energy and was heated. The heated image then transferred heat to the heat sensitive paper producing a blackened copy image of the original.

The first commercially available Thermofax machine was the Model 12. The 'layup' of the original and the copy paper was placed on a stationary glass platen and an infrared lamp and reflector assembly moved beneath the glass, radiating upward. The layup was held in position by a lid with an inflatable rubber bladder that was latched down by the user. In subsequent versions, beginning with the Model 17, the layup was fed into a slot, and continuously exposed as it passed the lamp and reflector. The Model 17 and successors were table top machines, approximately the size of a typewriter from the same era.

A variation of this technology was a billing system called the Q System, which was typically used by medical and dental offices. A 'master' composed of a sheet of heavy backing paper and a thin sheet of ruled paper attached to it at the top edge was created for each patient. Billing entries were then made in pencil on the thin sheet for each patient visit. To create a billing copy, a sheet of heat sensitive paper was inserted between the backing and the entry sheet and passed through the ThermoFax machine, usually a Model 47.

As copying technology advanced, Thermofax machines were subsequently marketed as a method of producing transparencies (viewgraphs) for overhead projector presentations. A sheet of heat-sensitive clear stock was placed on top of the original, and passed through a ThermoFax, producing a black image on the clear stock. This application saw common usage well into the 1980s, and specialized uses thereafter.

As of 2006, Thermofax machines were still widely used by tattoo artists. In addition to making copies, Thermofax machines can be used to make a "spirit master" for spirit duplicator machines. Tattoo artists use these spirit masters as tattoo stencils, to quickly and accurately mark the outlines of a tattoo on the skin of the person to be tattooed. Similarly, the spirit masters produced by Thermofax machines are also used by textile artists as a way of making a small, quick silkscreen.

The Thermofax process was temperamental. The coated paper tended to curl, and being heat-sensitive, copies were not archival. [cite web|url=http://www.archives.gov/preservation/holdings-maintenance/photocopying.html|publisher=The U.S. National Archives and Records Administration|title=Preservation Photocopying|accessdate=2006-09-14 "Archival records created by Thermofax, Verifax, mimeograph, ditto, and early xerographic processes are often very fugitive and should be copied onto archival bond paper."] The darkness setting was tricky to adjust, and drifted as the machine warmed up. Copy darkness often varied across a page, some portions of the text being too light and others too dark. Since the heat absorption of ink does not necessarily correlate with its visible appearance, there were occasional idiosyncrasies; some inks that looked nearly black to the eye might not copy at all, and an exposure setting that worked well for some originals might require a change to make usable copies with another.

Thermofax copies were inexpensive. One business book asserts that research conducted by Xerox before introducing their copier came to the conclusion that "nobody would pay 5¢ for a plain-paper copy when they could get a Thermofax copy for a cent-and-a-half." Fortunately, "Xerox ignored the research." [cite book|title=The New Positioning: The Latest on the World's #1 Business Strategy|first= Jack|last=Trout|year=1997|id=ISBN 0-07-065328-3|publisher=McGraw-Hill Professional [http://books.google.com/books?vid=ISBN0070653283&id=IOQNfYTocGgC&pg=PA143&lpg=PA143&sig=4spvIEsxbfuvAksy4sySayuq8Ko p. 143] . (The accuracy of the quotation is, however, suspect, as the company was not named Xerox at the time, and early Xerox leasing charges were far higher than 5¢ per page.)]

Contemporary references to the Thermofax process were not complimentary::They did have—what did they call that brown stuff? Thermofax, right. That's the first copying machine and they didn't look like anything at all. They were brown and they faded. [cite book|title=Water Resources People and Issues: An Interview with Theodore M. Schad|publisher=DIANE publishing|id=ISBN 1-4289-1247-9 [http://books.google.com/books?vid=ISBN1428912479&id=ikxmeGpkzuwC&pg=RA2-PA74&lpg=RA2-PA74&sig=U4oEynFJdNCoHNuUXZ6IzUQdDE0 p. 74] ] :Marjorie Spock had invested in one of the earliest models of thermofax machines, which she kept in her basement. It was a crude affair that continually overheated, belching smoke and vile-smelling fumes from odd sprockets and sending out scorched brown paper, sometimes completely burned and only barely legible at best. [cite book|title=Rachel Carson: Witness for Nature
first=Linda|last=Lear|publisher=Owl Books|year=1998|id=ISBN 0-8050-3428-5, [http://books.google.com/books?vid=ISBN0805034285&id=nf3pNCs70lcC&pg=PA320&lpg=PA320&sig=7xR8dCgVBCkTRxmv5UwVFwaxuOs p. 320] ] :The only thing we had then was what they called a thermofax machine, which was very strange. It was on a very bad tissue paper kind of thing and a very obscure image. But we were desperate and it was the only way to make copies. [cite book|title=The Art of George Tuska|first=Dewey|last=Cassell|publisher=TwoMorrows Publishing|year=2005|id=ISBN 1-893905-40-3|coauthors=Aaron Sultan, Mike Gartland, [http://books.google.com/books?vid=ISBN1893905403&id=HXP_XVHorGAC&pg=PA43&lpg=PA43&sig=RVNMwT10zBa3yastf6ogyVfaT6M p. 43] ] A Thermo-fax machine is used to copy plans for a bank security van heist in the British film Payroll (1961)

Cultural References

* Thermofax is the name of a dragon in the text adventure Wishbringer by Infocom.

ee also

*List of duplicating processes
*Duplicating machines
*Printing

References