Mark,
I am using a Da-Lite Contour screen 52"x92" with 1.3 cinemavision material. I have not noticed any hotspotting and the picture does look three dimensional at times. I know what your talking about with the reflective surface or emulsion as you call it but it is not visible with video. By the way I have seen a Stewart 1.3 gain screen and it does have this same sort of reflective material on it, but again you can't see it in the picture. I have the pro trim on my frame which is a black velvety substace that absorbs any overscan, it's great. I would suggest if you are building your own frame to add something like this to it. I don't have any experience with Draper. My projector is Barco Graphics 1209.
Rod
I am using a Da-Lite Contour screen 52"x92" with 1.3 cinemavision material. I have not noticed any hotspotting and the picture does look three dimensional at times. I know what your talking about with the reflective surface or emulsion as you call it but it is not visible with video. By the way I have seen a Stewart 1.3 gain screen and it does have this same sort of reflective material on it, but again you can't see it in the picture. I have the pro trim on my frame which is a black velvety substace that absorbs any overscan, it's great. I would suggest if you are building your own frame to add something like this to it. I don't have any experience with Draper. My projector is Barco Graphics 1209.
Rod