Chalk grounds

I am currently trying to collect some information regarding chalk
grounds. I am using a traditional chalk ground (rabbit skin glue)
for large scale tempera paintings. These paintings are large solid
oak panels (6x6 feet), which are properly reinforced and sized
before the ground is applied to the front. A problem that is
occurring however, is that with large fluctuations in humidity, the
chalk-ground expands and contracts (up to one cm), which I realize
is inevitable. My question is, whether there is some sort of
additive that could be mixed into the ground in order to make it
more resilient to these expansions and contractions without
cracking.

Alex Warren
Sinopia Pigments & Materials
229 Valencia St.
San Francisco, CA 94103

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                  Conservation DistList Instance 9:61
                  Distributed: Thursday, March 7, 1996
                        Message Id: cdl-9-61-025
                                  ***