My quilt guild had a speaker/workshop "Lizz Ploppert" who uses Plas-Tex which is shower stall walls. You buy it at home improvement stores and you can cut it with scissors. I bought a couple of her patterns and she had enclosed pcs of the plastic. It is a 3-d birdhouse that will open up into a mini-wallhanging. This plastic would make great purse inserts. I think she said that it sold in 4' x 8' sheets and you could probably have them cut it in half for you. She suggested you go in with a friend and share the sheet.