like title says guys I will have a optoma Hd20 soon and in a very dark room. Shooting on a wall 12 feet away from a shelf. My question is which one of these is best. I am clueless what the gain is all about but the http://www.buildyourownprojectionscreen.com/projection_screen_material.html screen is a 1.0 gain I believe. So any one with experience in this matter if they could help out it would be a life saver. I have been reading and reading on how to make a screen my only worry with the link I posted is getting wrinkles out.