Color plates may be manually deacidified and encapsulated in clear inert plastic film to allow continued use. Preservation photocopies are of value in providing paper substitutes for brittle books, especially those which receive heavy use or which are not well suited to microformat. Unlike preservation microfilm, however, a preservation photocopy does not provide a master which can be archivally stored for hundreds of years and used to produce additional copies on demand. The decision on how to preserve each brittle, non-repairable volume is made by the bibliographer responsible for its subject area, in consultation with staff from the Libraries' Preservation Division. When appropriate, the bibliographer also consults with relevant faculty members.
Every effort is made to ensure that the most suitable preservation method is applied.
In general this means that the preferred treatment for any damaged volume is rebinding or repair. When a volume is structurally unsound and too brittle to repair, the Libraries will try to locate a non-brittle paper copy, reprint, or later edition. Microfilm is normally the last alternative. Identification of brittle volumes involves library staff, faculty, and other library patrons. Library patrons who use damaged volumes bring them to the attention of the library staff.