In this workshop, students sculpt a head out of plasticine.
The next step is molding the head in a block of silicone.
After the silicone has set, the original plasticine sculpt is removed, and fast setting plastic is poured into the mold. (To keep the head light, this plastic will be just a thin coating.)
This shell is then "back filled" with a light but rigid foam. This means that the puppet head will be very light in weight, but strong enough to handle the animation process.