I’m with Noel - forget it.
I tried 60% film and although I was impressed with it optically, it was an absolute pain getting it perfect even when sandwiching it. I spent so much time and trouble then was never truly happy with it. When you’ve fiddled for ages you end up cleaning it every two minutes while you’re trying to get it right as it picks up the tinniest of bits. What a palaver.
I bought an acrylic one from mirrorworld in the end. 300x600 was about £35y. Really chuffed