Q: What type of plastic are these made of?
Q: is there a hole in the center?
Q: How much does the disc weigh?
Q: How thick are these discs?
Q: If there is no hole in the center how are you supposed to use it as an earring backer. I bought years ago in a jewelry store and they came with a hole so you can insert the earring post through it and attach the gold/silver backing that comes with the earring. I have in one ear a stretched earring hole and without a backing the earring falls off as the backing goes through the stretched hole in my ear?
Q: Do these come in other sizes or shapes?
Q: Can i make a hole in the disc then me putting color filter gel on the disc if I want to make a 3d filter wheel for my mini 3d capable projector ?