Microfilm quality control

I am interested in hearing from those who have conducted quality control
inspections on Research Publications microfilm from the 1970's and early
1980's.  Do you consider it "acceptable" microfilm, meaning that, from
your inspection of the film and your knowledge about the standards from
that time, you would judge that preservation effort to be adequate. I
have inspected positive copies of about 20 RP titles for bibliographic
integrity and targeting.  In most cases, the minimum standards were met.
Out of 20 titles, I did find 1 title with missing pages.  Pretty serious
error.  But, this is just a quick check of an over-used positive.  I
wonder if the master negatives would begin to meet preservation
standards for density, resolution, materials, storage, etc.  What are
your thoughts?  If you had an opportunity to microfilm a rare literary
title, and you discovered that RP had already filmed the title in 1975,
would you re-film? On what basis would you re-film?  Or, why would you
choose not to?

This is both, or either, a speculative question about all pre-1985 film
and a specific question about Research Publications quality control
during the 1970's.  Your comments are appreciated--posted either to me
directly or to the list.  Thanks.

Becky Ryder
Preservation Librarian
University of Kentucky

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                  Conservation DistList Instance 8:55
                Distributed: Wednesday, January 18, 1995
                        Message Id: cdl-8-55-009
                                  ***