Have you ever noticed the way an absorbent canvas negatively affects a painting? I've noticed several times how a painting, although it may look pretty solid when you're done with it, can begin to look rather thin and weak after a day or so, the paint losing it's body. This tends to occur mostly with commercial canvases. I have attempted to deal with the problem by going over the canvas with a layer of acrylic gesso but haven't noticed much of an improvement in the quality of the finished work. Solidity of the paint is very important and it's frustrating to see when a good painting sinks into flatness. Have you every experienced this problem? And if so, how have you dealt with it?