This likely has an answer that is escaping my google-fu this evening, but after about 2 hours of research and mixed responses reading through similar questions on various sites, I'm throwing in the towel and asking for help!
Some quick back story; at work we had 6 excess sheets of 6' x 4' styrene, about the thickness of two credit cards stacked on top of each other. We were using it for back drops in a display we constructed, and when I saw how resistant it was to damage I got the okay to take the excess sheets home.
I will be using them to build a ROTJ helmet following the WOF templates, but am concerned about the flexibility of the styrene. Do any of you have recommendations for how I should reinforce it? I've looked into fiberglass resin, but am concerned about the heat damaging the material. Any recommendations, or tips, are greatly appreciated.