Decorative absorption?

My new house theater/listening room is empty right now. The room is roughly 13.5' wide by 19.5 deep with a ceiling that slopes from 8' in front (where I am putting heavy drapes over the windows) to 17' or so in the rear.The floor is hardwood laminate where I have one area rug so far. The room is boomy as hell. My ol lady agreed that I can put some absorption panels on the side walls and ceiling if need be but she wants them to be "pretty" or something like that. Anyway, I got this idea of buying canvases, ya know the blank canvas stretched over wood frames(with the void in back stuffed with something appropriate) that you oil paint on and figuring out how to get prints to stick on them or actual acoustic panels that I could mount prints on. If anyone has ideas or experience let me know.