[EricH]

As far as my memory goes, plexiglass (acrylic) is not and has not been forbidden. In 2005, 330 used a sheet for one of their side armor pieces. It took a hit from a robot--that had traveled up the rather steep defensive wedge/outrigger on that side, mind you--and shattered into several large pieces. We replaced it with Lexan and had no further incidents of that sort.