What does it mean to preserve the collections that are amassed in the world's libraries? Our long-standing response to that deceptively simple question is probably still valid: to preserve is to keep information resources safe from decay, destruction, and loss; to ensure that they are findable; and thus to promote their use. Preservation strategies for books and journals achieve these goals through the implementation of procedures that improve the condition of an object or produce one or more usable copies accurately described in a library union catalog.