Hey Randy, (one more day before my golden email....) I have not constructed a frame for a fixed screen like you are, but in my first home theater I treated the walls (since it was a dedicated room) and was looking for a material to cover the walls with. I found that felt absorbed light very well. We did try other materials including velvet, but the velvet fibers seems to have a slight "shine" to them and did a little reflection of light as well. That was just for abient light and light coming out of the large screen TV, but if you shoot your Z2 at it, and any light floods outside the screen, you may notice it even more since the light is directed right at it. Plus, felt should be cheaper!
Either way, it will look nicer with a material on it vs. paint in my opinion.
