LynnG -- I was wondering if something like that would work, like I've seen the old pull down movie screens the type that used to be in Classrooms or meeting rooms or for showing vacation slides at the thrift store... was thinking that could really neat if I could indeed roll the thing up and stuff would stay relatively in place.
I do have a thin bamboo shade, the type for a sliding glass door. It sort of folds up as you pull the cord, I can see how that would work, not as ideal maybe in terms of being fully protected as a roller. You'd attach the flannel sheet along the top and probably along the sides within the area of the attached cords.