UK educational supply center centre Mindsets online sells variously-sized 3mm thick sample sheets of Eastman’s Spectar copolyester at not-completely-outlandish prices. Spectar supposedly looks and handles much like acrylic, but with the surprising property that it can be cold-formed without breaking or whitening, and exhibits a memory effect, holding a cold bend until reheated. Chemically, Spectar is similar to the PETE used to make disposable drink bottles, and is commonly abbreviated as PETG. Mindsets is the only online vendor I’ve found, so far, selling small samples of Spectar to consumers.