I'm glad to hear that worked. We've been thinking about the mirror sheets but the boys haven't started any real research or testing. This will go on their list. I also searched on thermoformable mirror materials, and saw a manufacturer claiming that PETG mirrors were easy to from with heat. The other plastic mirror materials that we've seen advertised are acrylic, mylar, and polycarbonate. If anybody has experimented with any of these, it would be great to hear how it went.