I use a 4 x 8 piece of Wilsonart laminate (formica) called "Frosty White" that I got at Mendards. If you need a grey screen, the Dove Grey works well, I've heard. It is a matte finish, does't hotspot at all, and looks excellent. I sent away for a lot of screen samples from Dalite and Draper, but didn't see much difference. I would guess it's a gain of 1.0 to 1.1. I pre-drilled holes in it, and tacked it to my wall--hangs nice and flat with no bulges. I then framed it with window trim painted flat black. Total cost: about $50. You can see all the colors at wilsonart.com. I really like this screen with my Sony 400Q, which is a 400 lumen LCD 16:9 projector. People's jaws drop when they see HDNET on this setup. Hope this helps.
mike