I just purchased a new Poly blend impact screen off of ebay. The price and discription seemed good. See below

MOVIE SCREEN IMAGE QUALITY. STRONG ENOUGH TO TAKE A REAL GOLF BALL. The Poly blend is commercial grade and designed for heavy use. The trade off is some grain in the image. If you hit alot of balls go with the poly blend.
SEAMLESS
SUPERTEX 9 OZ POLYESTER WHITE MESH
SEAMLESS YES YES
IMAGE QUALITY BEST GOOD
DURABILITY GOOD BEST
STRENGTH GOOD BEST

What I have found is there's a lot of grain with the screen. It produces a dull picture and there are interferrence patterns that look like small waves in a pond with light and dark patterns. The company is not very forth coming with info, so I was wondering if any of you folks have had the same issue. I have an epson home cinema 6100 projector.