Most fish, reptiles, and amphibians are cast in plastics (such as urethanes, polyester, or epoxy) because these materials are more permanent than taxidermy or freeze-dry specimens, and the finished models look more realistic. Molds are made from anesthetized specimens, usually with silicone rubber. Chase Studio is well known for the detailed coloration of these models. Snakes are often painted a scale at a time. Turtle shells are painstakingly colored to duplicate exact translucency. Frogs, salamanders, fish, and lizards are all painted with such precision that they are indistinguishable from the real animals.