n. reddish spotting of film or photographic prints caused by oxidation of the silver; redoxAnderson 1964Microfilm has the “measles.” It is an ailment baffling research scientists and causing some anxiety among businessmen, librarians and Government agencies, which are spending about $325 million a year to preserve records on film. ¶ Small spots tinged with red, orange or yellow have mysteriously appeared on processed negative film. The blemishes also take the form of concentric light and dark rings, or cause lines and printed letters to become broader and lighter.Morris 1970Not until 1940 did the government decide to fully entrust vital records to microfilm, and in 1965—as Calvin McCamy of the National Bureau of Standards noted at the conference—archivists were panicked by a fungus‐produced outbreak of “microfilm measles.” The fungus was traced to the cardboard boxes used for storing the reels.Hendriks 1986, 182The formation of microscopically small, orange-coloured spots—known today as redox blemishes—is well understood. They can easily be reproduced in the laboratory. In some reports these spots were called measles, an unfortunate term since it may suggest a disease, which could be contagious.MAPS 1992, 330The answer to your preservation microfilming needs ¶ Entrust your endangered material to MAPS ¶ Highest quality preservation microfilming—150+ line resolution images ¶ MAPS patented exposing system—Exceptionally narrow density ranges for better duplication ¶ Pofysulfide treatment—Protects your film against oxidation damage (measles)KDLA 20162.1 Thiosulfate residue content ¶ When not completely removed by washing during processing, such residue can consume the film’s emulsion and result in permanent damage. Archival microfilm must be free of this harmful chemical residue to ensure the film’s longevity and to avoid deterioration of the film’s emulsion through spotting or “measles.”NEDCC 2017In general, the environmental requirements of microforms resemble those of other photographic materials. Temperature should not exceed 70°F, and cooler temperatures are preferable. Year-round relative humidity lower than 50% is recommended for all film types. An upper limit of 40% is recommended for silver-gelatin films to minimize the likelihood of microscopic blemishes from silver oxidation (sometimes called “measles”).PEL 2019The boxes are constructed of a high quality acid-free (pH 8.5+/-.5) and lignin-free board that is buffered with 3% calcium carbonate to help prevent micro blemishes (also known as measles).
