I've been doing a bit of research, and I came across a material called Sintra. It's a PVC expanded closed-cell material, and is fairly rigid. I'm just wondering if anyone here has used Sintra for laser-cutting or in other applications (i.e. modding in place of ABS plastic)? If not, I'll give it a try to see how it works out...Initial research says that the fumes might be corrosive to the laser cutter...
Yes, the 'C' in PVC plastics is (PolyVinyl)"Chloride" and when cut with the laser gives off chlorine gas, which is dangerous both to the very expensive lens and our far more important lungs.
At the TechShop such materials are strictly forbidden in the laser cuter for the safety of their equipment and the operator, so I would strongly caution you to not cut this.
I have not really found much other than acrylic, wood, paper and leather that I cut. The spacers for my Elemental puzzles are cellulose acetate, but too thin and flexible for most 3D puzzle building.