Ethafoam sheets shrinking during transport

At the British Museum, we routinely use sheets of ethafoam to pack
objects when they go on loan. We have had several statues sent to
Mexico recently and to our surprise, in a number of crates, some
ethafoam sheets have shrunk considerably in size. (Fortunately the
objects concerned all appear unharmed.)

There seems to be no clear explanation as to why this has happened
on this particular occasion. To the knowledge of the couriers, the
shipment was not handled or stored in any conditions outside of
those normally encountered. All of the packing materials affected
have been in use for four years, but some crates with exactly the
same packing materials and length of use have remained entirely
unaffected. We are very puzzled by this phenomenon and wondered if
anybody had experienced something similar with ethafoam sheets.

Capucine Korenberg


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                  Conservation DistList Instance 26:3
                  Distributed: Saturday, June 9, 2012
                        Message Id: cdl-26-3-024
                                  ***