Butter paper on photograph

I have an old painted photograph (70 years old) pasted on paper
board, and found a butter paper pasted on back of the photograph
when I removed the backing board. My problem is how do I soften this
butter paper for removal (no softening in warm water--only choice
left is mechanical removal).

Can any one suggest me the materials used in making of butter paper
(used for interleaving in photo album)?

Madhavi Singh
Dharohar, art conservation centre
Lucknow, India


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                  Conservation DistList Instance 16:44
                 Distributed: Friday, January 17, 2003
                       Message Id: cdl-16-44-005
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