Note that the blinds sold by Focus DIY (and no doubt many other DIY stores) come in a variety which is a white, dimpled plastic which does not allow light through (so it's no good for back projection). Having already blown £900 on a projector, I did not have the funds to buy an expensive screen, so I experimented with one of these. A screen which gives me an 87" 16:9 picture cost me £50. Of course, these blinds need to be fitted to a wall or ceiling. It works very well.