Thanks for sharing this idea Lori, I didn't see it when it was first posted.
I have a tip too. My day job is picture framing and we always have offcuts of glass and acrylic. If you have a local picture framer, ask there, I know that if I was asked for small pieces I'd only charge a couple of bucks or on a good day give it away. We rarely use non reflective acrylic, so have very few offcuts, but we use non reflective glass a lot and have plenty. I took a couple of quick photo's with n/r acrylic and n/r glass (I found two pieces better than one). The first pic is acrylic and the second, glass.