I've just installed a freshly delivered 30H in my loft and I want to make my own screen on the end wall. I was considering using Digital light Grey from Goo which has a gain of 1.3 . I believe that the 30H is calibrated by Sim using a white screen wih a gain of 1.3. Will I see a big difference? Is there a white screen paint available with a similair gain. ( I want to use a paint so that I can maximise viewing area) I'd appreciate some feedback - I didn't get any response on the Projector screen forum.