Opportunity is missed by most people because it is dressed in overalls and looks like work. - Thomas Edison
I guess I can try two sheets contact cemented. The seem at 8 inches or so from that edge will be out of the image area anyway.Tried the big box store options (roofing liner, pond liner, shower liner, etc) They suck. They don't pull close enough to the frame, tend to wrinkle, some have weird textures that they show up in the mesh (both brands of pond liner were the worst), etc. I actually tested 3 other kinds of rubber off ebay as well and they all had issues with stretch or tearing. The nylon backed 3mm neoprene really is the best "cheap" option out there...just too small for those of us with huge frames.