Smooth-on i s acompany that makes various silicones and resins specficially to do what you are saying. They have lots of materials that they describe on their web site for creating the mold. what kind of mold release compounds to use and what kind of molding materials to use for what kind of resin you want to cast. There's a LOT of stuff to learn in mold making, but once you have it down, it's really pretty simple. Like everything else, though, it takes a bit of $'s to acquire the materials, though you can get them in pretty small quantities. Silicon's are expensive, in general.



they have lots of videos and data sheets and methods. ALl in all, good stuff!!

http://www.smooth-on.com