Preservation of microfilm holdings

We are beginning to work on a preservation program for our microfilm
holdings, consisting of just over 2,000 reels of filmed manuscript
collections.  In most cases, we have the originals of the filmed
material.  The oldest film was produced in the 1930s, the latest in
1991.  We are planning to store our master negatives off-site and keep a
printing negative and a positive copy on-site.

We have a number of questions about issues that must be faced in such a
program, including the following:

    --Has anyone set standards that film must meet physically to be
    considered "preservation negative" quality?  This is a special
    concern since many of our negative reels were produced many years
    ago.

    --If a newer negative copy in better condition exists, should it be
    considered the master negative in place of the older, original
    negative film?

If anyone has had experience with this type of project, we would welcome
any advice, comments, or warnings.  We think we have reviewed the major
pertinent literature, but we would appreciate citations of anything a
little off the beaten track.  Thank you.

Tim West, Manuscripts Dept., University of North Carolina at
Chapel Hill (TIMWEST [at] UNC__BITNET)

    **** Moderator's comments:
    The previous query comes from a person who is not on the DistList
    and will not see any responses that are posted here.  Tim has asked
    that responses be sent to Jan Paris (jparis [at] unc__bitnet).  If of
    general interest, please post it here as well

                                  ***
                  Conservation DistList Instance 5:33
                Distributed: Saturday, December 14, 1991
                        Message Id: cdl-5-33-010
                                  ***