In addition to DIY paints, we also provide information on commercial screen paints. These are a very viable option and some people would rather not mess around with the sometimes experimental world of DIY or don't feel comfortable mixing, or perhaps they just prefer something commercial over DIY.
There are probably more commercial screen paint companies out there than most people realize.
In no particular order or ranking:
Prices range from under $100 to well over $200. For some, the idea of getting something that isn't trial and error like DIY can sometimes be, the money is well worth it.
DIYTheater.com No Contrast screen paint kit
A thread by electronbee discussing his application of a DIY Theatre screen.