A bit off topic, but I thought it may spark some ideas..

http://www.blimpsign.com/index.htm#faqs

$695 just for the screen surface. I've actually toyed with the idea of micro or macro perforated rear projection screens on a small scale. The idea came to me from seeing some multicolored micro perforated backlit signs locally. It'd be nice if we could get it to work for a reasonable price. Then we could get true blacks from a projection. The following is a link to a film that a local sign shop may be able to provide samples. Clear Focus There are a lot of commercial manufacturers of rear projection screens that use micro perforations, but they've always been too expensive IMO.