I have a Da-Lite Imager Cinema Series 1.3 gain screen. I had noticed there was a very small sticky goo ball of sort towards the side of the screen. It was very small, however, wanting perfection I attempted to get it off via soap and water. BIG mistake. This wound up creating a small bluish tint patch on that part of the screen. Further attempts to remove it with soap and water and alcohol were ineffective. I queried Da-Lite about it and found out that the material is not washable at all and nothing can be used on it! Just dandy. It does not appear that having attempted to clean that patch caused any further damage, but had I have known this ahead of time I would not have tried to remove this foreign object. Fortunately you cannot see this smudge when a movie is playing, however, you can when a movie is not playing and you look at the otherwise white screen. This is going to bug me until the end of my days. Be warned if you have a similar screen.