I have been interested in this for the same reasons as you. I did a lot of reading and ultimately I tried nine different film types. Automotive “paint protection film” was the winner.
My thinking was this: “hard”, crinkly, low-stretch films like polyester, polypropylene, nylon, etc. are lightweight and strong, but they tend to very easily propagate tears from a small nick or puncture, some are very difficult to bond (i.e. “polycryo” crosslinked polypropylene), and most of them “haze” (become cloudy from innumerable tiny crinkle-lines) over time. Most “soft” films like polyethylene, PVC, etc. have much lower tensile strength than the hard films, so thicker (heavier) stock is required. Also, many film materials are very sensitive to UV radiation, and rapidly yellow and break down in sunlight. An ideal tent window material should be crystal clear, resistant to crinkle-induced hazing, strong enough to permit use of thin (lightweight) stock, UV-resistant, and resistant to tear propagation.
Urethane “paint protection films” (also called “leading edge film”) has all of the desired properties. It contains UV stabilizers, it is very strong and resistant to punctures and tears, and it is crystal clear and doesn’t haze or yellow. It is lighter, stronger, and more UV-resistant than PVC film, which is the usual material in tent windows. Many paint protection films have adhesive on one side, but this can easily be removed with alcohol.
I hope this helps.
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