Just playing around with the scrim I made a while back. It’s roughly 1.5x2m with a frame made from 21mm plastic waste pipe (B&Q sell this along with all the corners, T pieces, 45 degree corners etc. to make any kind of frame you want). The surface is Translum plastic which is made by Savage. You can buy it on a roll 1.5m wide. The idea is to project light onto the scrim so that it drops to nothing before it reaches the edge of the scrim – and so there’s no edge visible. You can also try projecting patterns using something like the Lightblaster however on this occasion I just wanted a classic ball of light with a nice gradual drop-off towards the edges.