Transferring fossil specimens from stone

I am currently working with a collection of fossil fish and plants
embedded in stone. This is a collection consisting of a few hundred
specimens, collected sometime in the 1960s-1970s and partly worked
on by palaeontologists during the 1970s. A few of the fish specimens
were transferred into polyester resin casts. Depending on the
polyester product and the resin-hardener mixture, some of these
transfers have yellowed very considerably over the years. Since
there is now a renewal of palaeontological research on this
collection, I'd like to ask whether there might be a non-yellowing
transfer material that could be best used for transferring fossil
specimens from stone. How about products from the acrylic family,
paraloids and such? Some of these do not yellow, but I haven't heard
of them being used as transfer material. Is yellowing polyester
still the main product used for embedding specimens so that they can
be seen from both sides?

Gali Beiner
Conservator
Palaeontology Lab
The Hebrew University of Jerusalem
Israel


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                  Conservation DistList Instance 16:53
                  Distributed: Tuesday, March 18, 2003
                       Message Id: cdl-16-53-014
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