Paint is a great option Jason...if you are willing to live with a Chroma Green wall! LOL There are many, many sites out there for Chroma key screens. some better than others. I bought mine as a 12'X12' backdrop that has loops and it fits on my backdrop stand perfectly. There is a problem with a Backdrop cloth though. It wrinkles easily! The smoother the screen, the easier it is to key. I end up steaming mine each time I use it. You don't have that problem with a wall, but it is not portable either. I use mine for Stills as well as video and love the portability. I have seen this formula for the paint before and have heard good things about it. It IS expensive (last I heard about $35-$40.00 per gallon), but a good alternative to a backdrop. The other problem with a backdrop is unless you get a heavy thread count (thick) muslin or canvas drop, Light WILL shine through it in the sun. My backdrop from Adorama cost $79.95 (free shipping). I use it in After Effects and us Red Giant Keying software which is a perfect match.