Subject: Marking microfilm
The Library of Congress has been marking its service-copy microfilm with a perforating machine that punches out the letters "LC". The machine was designed to perforate paper, not film. With the increasing use of polyester as a film base we find that the perforator sometimes fails to perforate cleanly, which creates cut edges that are out of plane with the rest of the film strip. Also, a recently purchased perforating machine leaves a slight oil residue on the film that only show up when a finger is rubbed over it. We aren't satisfied with this perforating system for marking service-copy microfilm and would be interested in learning how other institutions are marking their film to show ownership. Merrily A. Smith National Preservation Program Office *** Conservation DistList Instance 7:9 Distributed: Thursday, July 8, 1993 Message Id: cdl-7-9-005 ***Received on Wednesday, 7 July, 1993