Leo, the JTP material is 3mm. A small piece wouldn’t weight very much, but it only comes in 12×12 inch sheets or larger. For a little window, butchering a pair of goggles would probably work fine.
I didn’t realize you had designed the shroud to float. I had thought about a design like that, but was worried about catching on the work surface.
On a whole other subject: has anyone tried laser engraving a ceramic floor tile? The only thing I’ve been able to find on youtube is someone using a 40w C02 laser to etch tile. I might give it a try – probably have to go real slow.