Thickness of diazo film stock

Pam Bjornson <pmb<-a t->nlo< . >nlc-bnc< . >ca>, on behalf of Myriam McCormack
<myriam.mccormack<-a t->nlc-bnc< . >ca> writes,

>    It appears that there are fewer companies currently
>    manufacturing .7 mil film for use as diazo microfiche.  Many
>    companies are now using film that is .5 mil and our service
>    bureau has suggested that we could switch without any loss of
>    quality or durability.

Assuming you do mean *microfiche*, as opposed to rollfilm (there's
some tendency to use the terms interchangeably), the ruggedness of
the 5 mil material should be adequate as to the possibility of
tearing, however I should think it would be more vulnerable to
accidental buckling, folding, and other consequences of rough
handling. Too-thin film in *roll* form is more subject to jamming,
stretching, twisting, etc.--in film readers and other film transport
devices.  I always think fiche should have sufficient thickness so
as not to be "limp" or "droopy" in handling.

Charles Stewart
Sr. Photographic Technician
Library Photo Service
U.C., Berkeley

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                  Conservation DistList Instance 11:10
                   Distributed: Friday, July 18, 1997
                       Message Id: cdl-11-10-009
                                  ***