[RacerX45]

Just a word of caution - if you over catalyze polyester resin it can catch on fire. Also, polyester resin is very brittle and can shatter if dropped. If you are going to convert these into animated skulls, you might want to use a 2 part urethane resin. They make high strength resins (such as Task 2 by Smooth-On - I use this to make prop helmets) that would probably work well for this application.

Randy

 

[RacerX45]

Sorry, forgot you want it to be clear. Clear urethane resin is tricky and expensive. You don't necessarily need a silicone mold as long as you use the correct release agent.