Q. Ive varnished my paintings through the years. Now, it seems the varnish has almost disappeared. Im completely at a loss as to what to do to restore the brilliance. Do you have some advice about how to fix my paintings?
A. All varnishes eventually begin to deteriorate with time and some, like the natural resin varnishes, deteriorate faster than others. As the varnish surface oxidizes it crazes (or cracks) a bit, becomes duller and sometimes even loses its transparency. In order to re-varnish a picture safely, its necessary to first clean the picture surface. Years of accumulated dust and grime must be cleaned off with solvents after careful testing by conservators, lest this stuff become trapped beneath the layer of new varnish. Usually, the old varnish is removed—or, at least, the surface of the old varnish is removed. If your paintings are valuable, this is a job for a professional conservator. Only a conservator will be able to find out which cleaning solvent(s) will be appropriate for the type of varnish and paint in the painting; an artist doing this kind of work could easily destroy the picture.
Judy Buswick is a freelance writer on the arts. She lives in Chelmsford, Massachusetts.