I use Bondic a lot for small parts and no mold release is required. It is advertised as a "glue" but it hardly sticks to anything. It does come out with a slightly sticky feel and clouds when touched so a spray with acrylic clear takes care of that. This stuff is so easy and quick to use that I don't get why everyone keeps looking for something to cast small parts when this material is available. It should be in everyone's toolbox. Resin is the most user-unfriendly material I ever used ... unequal mixing ratio, VERY expensive, especially for small parts, as shelf life makes me throw out 95% of it, bubbles everywhere to fix, wait for it to cure and just plain nasty stuff, IMO. I use Silicon rubber 2-part molding putty