GLASS: http://www.glassdoctor.com/santacruz/ http://santacruzshowcase.com/color-glass.htm --these folks focus on showers, but this page is on colored glass. if we can get something that's white and translucent, but IR transparent, we may be able to avoid having to get a projection screen. Chris - rough estimate on 4'x6' ~$338 (including tax) -- possible sponsorship. (831) 234-1983
Home Depot.com indicates that Home Depot may very well be useless to us for glass needs.
Classic glass - roughly $100 for a 4'x6' sheet at 1/4" thickness - (831) 423-5054 roughly $150 for 3/8" thickness