Meli and Terry,
Thanks so much! Meli, the article is new information for me, especially the "fat over lean," which makes sense. I did use increasing amounts of Liquin as I painted, without even realizing this is the right way to go.
Thing is, the skin or top layer of paint lifted right off the old painting, which is about 12 years old, Terry. I did use liquin for many layers, but it just lifted right off, only in one spot. It's not completely dry underneath, I don't think. I patched it, but it scares me. This painting took all winter to complete. I wonder if sitting it on the mantle over the fireplace, which heats my house, might have done it. It wasn't like a blister, more like shutters opening on a window. Just a small spot, but it scares me. Any thoughts?