Using vesicular/diazo film for service copies

Are there any institutions out there using either vesicular or diazo
film for their microfilm service copies?  Northwestern has been using
only silver halide for service copies.  Some of our preservation
microfilm silver copies are being scratched when users read them.  Our
microfilm readers are serviced frequently--however, high demand titles
do get scratched.  That led me to think about using either diazo or
vesicular film for service copies...any one with experience out there
with any information or suggestions?  Thanks.

Elayne Bond
Head, Materials Processing
Northwestern University Library
1935 Sheridan Road
Evanston, IL  60208-2300
708-491-8654
Fax: 708-491-8306

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                  Conservation DistList Instance 7:87
                   Distributed: Friday, June 3, 1994
                        Message Id: cdl-7-87-008
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