Discarding acetate microfilm masters

Jennifer Lloyd <jlloyd [at] nla__gov__au> writes

>We have commenced a project to create new polyester microfilm
>masters of collections for which we hold prime preservation
>responsibility (we own the master). The new polyester master is
>created via direct contact copying from the original acetate camera
>master. It is not possible to refilm these collections. This means
>that the new polyester master is a second-generation film. The issue
>I am grappling with is this: Should we discard the original
>cellulose acetate camera master?

I would not recommend discarding the acetate masters for two
reasons: 1) even if the duplication is done correctly, the new copy
will have slightly less resolution (image sharpness) than the master
and the copy from that copy will have even less.  Make one copy and
see the difference in the resolution target using a microscope.  If
there is no target, print out a page with small print and compare
them.  2) at some point  in the future, the library may decide to
digitize its microfilm and it would be much better if the transfer
could be done from the master than from an inferior copy.  My
suggestion would be to store the acetate masters in cool or cold
storage in a different location as a disaster backup and for such
time as they are needed for digitization.

Gary Saretzky
Archivist, County of Monmouth


                                  ***
                  Conservation DistList Instance 20:19
                  Distributed: Monday, October 9, 2006
                       Message Id: cdl-20-19-006
                                  ***