Poly-Optic

Pete (tutor) recommended that I consider using Poly-Optic resin as a casting medium. He used it to cast a tongue and it gave a very fleshy appearance, but is rock-solid and UV stable. You can see the tongue on his blog: http://ptfxwerewolf.blogspot.com/. It is made by Polytek, and gives a water-clear appearance and excellent detail. The process seems tricky, but it may be worthwhile. The official gúmpf about it can be found at http://www.polytek.com/products/14recent.pdf.