15. strange spots: Lawson B. Knott, Jr., “Aging Blemishes on Microfilm Negatives,” General Services Administration Circular, no. 326, January 21, 1964. See also Ellen McCrady, “The History of Microfilm Blemishes,” Restaurator 6 (1984). McCrady observes that microfilm’s fineness of grain causes problems: “Silver, normally a stable material, becomes more reactive when finely divided. As a result, silver halide microfilm is more strongly affected by processing, humidity and various oxidizing gases and contaminants than many other types of film.”
16. “attacked metal filing cabinets”: Susan Cates Dodson, “Microfilm — Which Film Type, Which Application?” Microform Review 14:2 (spring 1985).
17. “complete image loss”: Carl M. Spaulding, “Kicking the Silver Habit: Confessions of a Former Addict,” American Libraries, December 1978.
18. Dodson measured the temperature: She also quotes Peter Adelstein of Kodak: “Examples of image loss have been observed after short exposures to 150°….The essential fact to keep in mind about vesicular film stability in that even very short exposure times to elevated temperatures will destroy the image.” Peter Z. Adelstein, “Preservation of Microfilm,” Journal of Micrographics 11:6 (July/August 1978), quoted in Dodson, “Microfilm — Which Film Type.”
19. serious light-damage: Mark Jones, Fading of Diazo Microfilms in Readers, NRCd Publication 10 (Hatfield, England: NRCd, 1978), cited in Dodson, “Microfilm — Which Film Type.”
20. certain species of fungi: Aspergillus, penicilium, alternaria, and cladosporium, for example, can grow in the gelatin emulsion of film. See E. Czerwinska and R. Kowalik, “Microbiodeterioration of Audiovisual Collections,” Restaurator 3 (1979).
21. easily scratched: “Silver film is easily scratched and abraded. Small foreign particles and the sharp edge of a poorly designed or out-of-adjustment reading machine will both gouge away the thin, soft gelatin emulsion as roll film is wound back and forth in use. In the main, this type of damage happens to such frequently used film as recent years of major newspapers; but a pristine roll of film can be badly scratched in a single use, particularly in the hands of an unskilled person.” Spaulding, “Kicking the Silver Habit.”
22. “extreme susceptibility”: Spaulding, “Kicking the Silver Habit.” See also Philippe Rouyer, “Humidity Control and the Preservation of Silver Gelatin Microfilm,” Microform Review 21:2 (1992); and Peter Adelstein, “Status of Permanence Standards of Imaging Materials,” Journal of Imaging Science and Technology 36:1 (January/February 1992).
23. check of master negatives: Erich J. Kesse, “Condition Survey of Master Microfilm Negatives, University of Florida Libraries,” Abbey Newsletter 15:3 (May 1991), palimpsest.stanford.edu/byorg/abbey/an/an15/an15-3/an15-313.htm. Kesse writes, “Mold was the primary or partial cause of deterioration of 64 % of cases.” And the master negatives weren’t always master negatives: “Further examination of the entire master negative collection revealed a distressing fact. 12 % of master negatives were acetate- and polyester-based diazo copies. Another 40 % of the masters, while silver-gelatin emulsion, were not first generation film.” Some of the damage that Kesse describes sounds relatively minor; on the other hand, a bit of foxing that might on paper obscure a single letter may blot out a portion of a paragraph on film.
24. “there seems to be a much wider”: James M. Reilly, et al., “Stability of Black-and-White Photographic Images, with Special Reference to Microfilm,” Abbey Newsletter 12:5 (July 1988).
25. original draft: The draft title was “Are Your Microfilms Deteriorating Nicely, Librarian?” Clapp papers, Library of Congress. In 1957, Clapp correctly wrote that microfilm’s “dangers of deterioration are even greater” than those of paper, because they are “less easily detectible and more devastating.” Council on Library Resources, First Annual Report, 1957, p. 20. In the next year’s report, he writes that “though microfilm is widely used to provide a permanent copy in place of the impermanent original form of the newspaper, it has been found that microcopies are themselves subject to deterioration. This is all the more dangerous for being much less easily detected” (p. 25). Eventually, though, Clapp stopped talking about the dangers of microfilm deterioration and stressed the dangers of paper deterioration instead.
26. “excessive residual hypo”: Robert C. Sullivan, “The Acquisition of Library Microforms: Part 2,” Microform Review 6:4 (July 1977), p. 210.
27. “in more than 50 percent”: Sullivan, “Acquisition,” p. 210. In fiscal year 1972, for example, 589 units were tested, and 356 were rejected; in fiscal year 1976, 639 units were tested, and 266 were rejected. “It must be emphasized,” Sullivan writes, “that rejection by the laboratory does not necessarily mean rejection for addition to the Library’s collections. In fact, since the majority of microform units purchased for the Library are 35mm microfilm reels of newspaper files, and many of these are non-current files dating back fifty to one hundred years or more, many of the ‘Rejections’ noted by the laboratory are for reasons such as loss of text due to uncut bindings, original damaged or mutilated, leader and/or trailer insufficient, or incompleteness. If, after consultation with the Recommending Officer, it is determined that the best or only file available was filmed, then the decision may be made to accept the film.” Sullivan offers some reassurance, however, saying that the lab’s recommendation to reject film is accepted when the flaw or combination of flaws is “considered fatal, such as excessive hypo content, pagination inverse, splice in positive film, non-silver emulsion film stock, or lack of clarity or readability.” Buying flawed film is not in itself an act of irresponsibility; buying flawed film to replace originals is.
28. trance-inducing job: In the mid-sixties, the Library of Congress’s Photoduplication Service, including the Newspaper Camera Room, had a “high rate of staff turnover, exceeding 40 percent overall, with correspondingly increased difficulty in recruiting qualified replacements.” Library of Congress, “Administrative Department — Office of Collections Maintenance and Preservation,” Library of Congress Information Bulletin 25:41 (October 13, 1966).
29. “invisible product”: Allen B. Veaner, “Crisis in Micropublication,” Choice, June 1968, pp. 448–53.
30. “Serious defects”: Veaner, “Crisis in Micropublication.” Carl Spaulding, in “Kicking the Silver Habit,” says that “few libraries test their silver film acquisitions, few know for sure whether those micropublications have been processed according to archival standards.” Because The New York Times is heavily used, librarians discovered the problems with its filmed copies, beginning in September 1967, almost immediately. There was, Veaner writes, a “precipitous drop in technical quality” after the Times bought Microfilm Corporation of America and ended its arrangement with University Microfilms; some pictures appeared as “unintelligible blotches of grey, black, and white”; “it was reliably reported that the newspaper’s research staff was unable to utilize its own product.” Eventually, the Times refilmed a stretch of months; now Bell and Howell/UMI, formerly University Microfilms, is producing the film. See Allen Veaner, “New York Times on Microfilm,” Choice, December 1968.