For the past fifty years or so, one of the most common items of discussion at coffee houses, seedy drinking establishments, art fairs, mailing lists, or wherever painters congregate to argue and expound their craft; has been the many advantages or disadvantages of oils versus acrylics as a painting medium. It's right up there with the chicken-egg controversy only perhaps a little more relevant. Setting aside the various technical elements of trying to borrow from each the various assets, leaving behind the liabilities, there inevitably arises questions regarding longevity--how long with they last? ("They" usually meaning acrylics). Of course, seen as a "given" is that oils will last an eternity plus a decade or two. Actually, nothing could be further from the truth. Especially with oils, there are too many variables--painting technique employed, painting ground preparation, fat over lean, quality of pigments and binders--the list is nearly endless.
Okay, take it from me, with no special care, I know acrylics last for at least 20 years. I've got some that are 22 now, in fact. Of course that's a mere moment in art history and the conservational horror stories DO abound. But insofar as there have been problems with polymers in the past, there are two or three factors involved. One, many of the paints used by Abstractionists (the first group to really encounter polymer media) in the fifties, were NEVER intended by their manufacturers to be artist quality. They were used because they could be bought in BULK, given the incredible quantities artists like Pollock went through on just a single painting. Second, in many cases, these artists were still struggling financially and bought products based upon PRICE rather than quality; and as we all know, then, as now, you get what you pay for. And a third factor is that in the early days of synthetic media, they were still highly EXPERIMENTAL. That is, they weren't what they are now. Any or ALL of these factors play a part in the archival problems involving acrylics which are being combated today in museums across the country.
So, it cuts both ways. Many of Albert Pinkham Ryder's oil paintings, for instance, are conservators nightmares because of his misuse of oils. He's reported to have use BACON GREASE (forgodsake) as a thinning medium with his oils. Some of his work was done on the back of WALLPAPER or window blinds. I guess I shouldn't talk, some of my first oils as a teenager were painted on POSTERBOARD. On the other hand, with the advent of acrylics, many artists, especially in the beginning, thought they could get away with painting on literally ANYTHING. Conservators now know that's not the case. To sum up, the consensus seems to be that oils CAN be extremely archival, lasting millenniums, yet they are also quite fragile and subject to exacting demands as to their use and care in order to attain this level of permanence. Acrylics, on the other hand, are more forgiving along this line. Like oils, they CAN, and have been, misused, but in comparison tests, under ideal conditions, in which the effects of aging have been accelerated, they often fare BETTER than comparable grades of oils.