Here is the problem I believe I am seeing with the spandex screen - resolution. I went to Jo Ann's after work and got a few fabric samples, flat white, shiny white, and shiny silver. The idea behind the shiny material was to be used as a backing to potentially brighten the spandex image. Well when I put up the matte side of the shiny white fabric it looked sharper than the spandex. Then I tried the silver matte side, and eventually the silver shiny side. The silver shiny side offered the best contrast of anything, dark blacks similar to the gray spandex, but brighter whites. Since I was just taping it up over the current screen it was not tight, but I was able to make the center part fairly tight. The areas that had ripples did not look good, hot spotty, but the flat tight section looked good. I am guessing this is a similar effect as with the Silver Fire paint.
The flat white fabric (I think it was called Muslin) was not good, it was the worst of everything I have tried. Hard to describe other than low resolution, and seemed to make the overall picture looked washed out unlike the matte side of the shiny white fabric.
So I am washing the gray shiny material to clean and remove wrinkles to try this again with it mounted and stretched properly with no ripples. More later on this. The matte white side of the shiny white material is still up for consideration with sports as well but I want to try this shiny silver material first.