Plextol B500 impregnation stains on paper

I am a student in paper conservation and I'm treating a watercolor
on a paper that had almost no sizing at all. I had to line it and
even if the colors were not water sensitive, I decided to use a
Japanese paper prepared with Plextol B500 (1:4 in water) and then
reactivated with ethyl-alcohol. During the lining process, some
adhesive 'bled' into the work especially in the edges of the tears
and left some dark stains.

I unlined the work and tried to remove those stains with different
methods but none was efficient: immersion in ethyl-alcohol,
cataplasm with atapulgite+acetone, cataplasm with
atapulgite+toluene, immersion in acetone, immersion in toluene,
immersion in xylene. (immersion time went up to an hour and still no
result) Do any of you have some advice to help me get rid of those
stains?

Camille Dekeyser
Rue Hotel des monnaies
1060 Bruxelles


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                  Conservation DistList Instance 25:48
                  Distributed: Friday, April 27, 2012
                       Message Id: cdl-25-48-014
                                  ***