Interleaving

In Cons DistList Instance: 9:52, I wrote

>I am writing to ask advice on interleaving a very large and valuable
>volume of 100 hand-colored engravings dating from the 1830s.
>Particularly with some of the darker, larger images,  there is a
>fair amount of offsetting onto the preceding plate.

I believe the imprecise language in my previous posting has led to
misunderstanding, so I'll attempt to clarify.  The type of
"offsetting" that I am describing might more appropriately be called
staining or image migration.  It is associated with dark pigments
(grays, blacks, and browns are the worst) used in the hand coloring.
It affects more than the plate immediately adjacent to the image, in
the worst cases.

My questions are: is this likely to be a continuing process after
160 years? If it is, will interleaving do any good?  If interleaving
would not be effective, what else might be done?

A private correspondent (thank you, Gary Frost) has given me some
helpful leads.  After I've followed up on these and informed myself
a bit more on the subject, I will post more specifics if it seems
warranted. In the meantime, additional information would be welcome.

Elaine Smyth

                                  ***
                  Conservation DistList Instance 9:55
                Distributed: Wednesday, January 17, 1996
                        Message Id: cdl-9-55-007
                                  ***