Generally, before microfilming a book, newspaper, or collection, it is important to discover whether or not the title has been filmed by some other institution. If the library belongs to a consortium, has access to an interactive bibliographic database such as OCLC or RLIN, can access an up-to-date list of master microforms for the region, or has printed lists of filmed titles, some careful checking should be done before the risk of duplicate filming is taken. However, given the generally poor standard of microfilm storage, claims by other institutions of having the microfilm available for purchase should be treated with caution, especially for titles filmed ten years or more ago. The preservation professional should use careful inquiry to discriminate between credible and suspect film holders.
Titles that are microfilmed should be fully catalogued. If possible, the interactive database record should be marked to show that the title has been "queued" for filming. This informs other libraries that you intend to film the title. Filming must be done soon after the queue has been recorded. When the filming is complete, the record should be altered to reflect that the title has been filmed and a new record created.
Over the last several years, printed lists of master microforms have been published for various regions of the world, and while these are useful, there is inevitably a publication lag, with some microform created but not reported for one to two years. Lists, whether paper or electronic, reflect only those titles reported to them, and there is no guarantee that older film will be usable. Clearly, an active consortium of dedicated librarians could play a critical role in reversing this problem.
Materials queued for microfilming should be collated to ensure completeness and should have eye-legible targets to be captured, along with the title, by the camera (see FACILTIES: SPACE AND LOCATION: Microfilm Preparation). There are standards for bibliographic and technical targets to ensure consistency of approach. See http://www.nla.gov.au/preserve/trainmat.html for detailed instructions on microfilm processing.
Special processing
Protection for microfilm can be improved through the use of polysulfide treatment, which greatly retards damage from pollutants. Polysulfide treatment, developed by the Image Permanence Institute of Rochester, New York, USA, can be added at the film-processing stage. Polysulfide solutions prevent "redox" blemishes by converting a percentage of the silver in the film into more stable silver sulfide. The treatment can be used during initial processing of film or for film already processed.
