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Subject: Diazo microfilm

Diazo microfilm

From: Michael McCormick <aa683>
Date: Thursday, March 2, 1995
Charles Stewart <cstewart [at] library__berkeley__edu> writes

>As to whether or not these materials "self-destruct,"  I suppose it
>could be said that they do so, mainly because the image is composed of
>dyes which are bound, eventually, to shift and fade.  The action of
>light is a catalyst for this type of deterioration and it stands to
>reason that service copies will be exposed to intense light (in the
>reading/printing machines), especially the more popular items.  We've
>had diazo films submitted for duplication here which are no longer
>legible due to fading.

I have inspected a record series on diazo that has, essentially, been in
dark storage in a bank vault since its creation in the mid-1970s. It
shows approximately a 50% density loss.  Therefore, light exposure must
accelerate the process, but does not initiate it.

Also, the film is developing vinegar syndrome.  It has been my
understanding that this is a hydrolysis reaction.  Does it seem likely
that the outgassed ammonia can trip the reaction?

Michael McCormick

                                  ***
                  Conservation DistList Instance 8:70
                   Distributed: Sunday, March 5, 1995
                        Message Id: cdl-8-70-003
                                  ***
Received on Thursday, 2 March, 1995

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