Will a painted wall do a decent job as a temporary screen for a projector? I have a projector but no screen, and I just bought a house with a room that I am going to dedicate to HT, but I don't have a screen, nor the money to buy one. Will a white painted all work? If so, should it be glossy, semi-gloss, flat, etc? I will eventually buy a screen, but the WAF and money are holding that idea back. I think if I show her how good it can look, she will cave in and let me purchase a nice screen.