The purpose of this study was to identify the central values and the range of variability for costs associated with selecting and preparing books for microfilm preservation, filming, and maintaining quality control and adequate records. The study was based on data supplied by the libraries at the University of Chicago and Columbia University, the New York Public Library Research Libraries, and the Library of Congress, as well as site visits to each library, interviews with key personnel, detailed work logs kept during the first six months of 1986, and work sampling data collected during the same period. Considerable variation was found in the unit costs of the library-specific processes of decision making and preparation and review, with smaller variations in the costs of the film work itself. The data suggest that the path to greater efficiency is in the development of large processing centers, with careful attention to the problems of record management and administration. (CGD)