MITRA Forum Question Details

I am not an expert in preventive conservation, housing, or storage but my gut instinct is that the darkening is a result of dark aging or too much binder, or a combination of the two. However, before suggesting anything, I have forwarded your question to a moderator more knowledgeable about those subjects. I may be off the mark on this.

​Here is a response from Hugh Phibbs

Proximity to ligenous cardboard can produce a number of pollutants, peroxides and acids, most prominently, and these oxidants could interact with the chemistry, of the paint, but we have seen so many factors enter into instability of paints, that it is hard to point to anything in the storage materials, in particular. Styrene monomer has long been suspected as a change agent in preservation setting, but the research is scant. What may be safest to say is that this is an oxidation reaction and that the storage setting did little to inhibit oxidation.

​As to what you can do, and if the work does not contain any light sensitive or fugative colors, put the painting in a place that receives indirect sunlight for a week or so (not directly in the sun unless that is only far a very, very short period of time) and see if some of the yellow cannot be bleached out. If you see some beneficial but incomplete effect, try another week.