RTV is a two-part silicone rubber used in making molds for jewelry. It takes heat quite well and conforms to intricate items without becoming stuck to them. This made it ideal to use as the mold for my acorn.
Wow, that sounds cool. Is it the same RTV silicone you can get at the autoparts store in a tube? Is there anywhere I can get more info on how to make molds? Do you have to heat the RTV once you place the medium you're using in it? For instance, if I used FIMO clay, could I heat the clay in the mold or would I have to take it out of the mold? I know I have asked alot of questions and I understand if you don't feel you have the time to answer them. I'm going to google it too. The answers provided by you folks so far have been extremely helpful.