Tussaud's Casting Wax

Wax’s similarity to human flesh has made it one of the best materials for mimicking human skin in theatrical prosthetics and waxwork models of famous people: this sample of Tussauds casting wax is a special blend of paraffin wax, beeswax and sometimes sumac (Japan) wax. 

Waxes are distinguished by their malleability, which is why they are such a great material for drawing and sculpting (see our scopas modelling wax and terracotta modelling wax). Waxes have a crystalline molecular structure which is a lot like a metal’s: under a microscope both waxes and metals are made up of lots of tiny crystals, called grains, which are tessellated together in a pattern that looks a bit like crazy paving. When you squish a piece of wax you are forcing these tiny grains to stretch, bend, and slide past one another. When these crystals are smaller and more irregularly arranged they can more easily move past each other, and the wax is more flexible and malleable. 

Waxes are not just used to mimic the body - because it is biocompatible, wax has been used in and on the body for a very long time. There is some evidence from Slovenia to suggest that beeswax was used as an early dental filling around 6500 years. We even have a sample of artificial eye wax that is used by prosthetists to create a temporary model of the replacement eye that can be tested in the eye socket and easily adjusted to make it comfortable before a permanent glass or acrylic resin version is made.