1/4" Lexan. About 40" x 44" insize. Went with gray tint for the skylight.
Quickest way to cut, is use a 4 1/2" grinder with a metal cut off blade (3/32 thick).
I like using a 3/4" plywood sheet to help clamp the plastic down. I had been using some 1/4" thick aluminum I had, but you don't want the cutoff blade hitting it. It did make a nice spacer, so I would use the nut on the blade to space the blade about 1/4" away.
Much easier to use plywood and a dark sharpie line on the Lexan only allowing the blade to penetrate the plexi by 1/4" or so.
