Some years ago, some friends and I were playing around with a DuPont product called Tefzel. It's a clear sheeting, comparable to common poly but much more transparent, much stronger, and, most astonishing of all, apparently immune to breakdown in sunlight. I had priced a 20x20 piece for a small
greenhouse around the year 2000, as I recall, and was quoted something close to $1000!! I decided I could replace common poly many many times to get to that! But we did get some free samples since my friend was making
solar panels and wanted to try it as a covering. I had some scraps paper-clipped together over a coil of black hose on my cabin roof for a
shower water heater.....and they were still intact, flexible, and transparent ten years later!