Identification of acetate negatives

While recently surveying a small collection of negatives at the
Institute, it was noticed that some of the material had developed
blue or pink stains on the back of the film (in the anti-halation
layer?).  The bulk of the material appeared to be nitrate (date,
format, yellowing of the base) but these stained items confused me.
Does this staining appear *only* on acetate film, or can it also
occur on nitrate? Any information would be gratefully received.

Cheryl Jackson
Paper and Photographic Conservator
Australian Institute of Aboriginal and Torres Strait Islander Studies
+61 6 246 1175
Fax: +61 6 249 7310

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                  Conservation DistList Instance 9:69
                   Distributed: Friday, April 5, 1996
                        Message Id: cdl-9-69-016
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