This is a plaster mould that I made of a Chavant oil clay sculpture. The intention for this was to brush silicon rubber into the interior of the mould to create a skin. I then created a fibre glass interior that could be articulated to create a puppet.
Here's the finished sculpture.
The first step is to block the mouth up. This is because the teeth will be cast separately.
A clay wall is then built up around the edge of the sculpture. This will define where the two parts of the mould meet. I used water based clay for this so that it wouldn't disturb the sculpture. I did insert some thin pieces of wire to provide support however.
Make sure to cut some keys and guidelines into the clay. These will be picked up by the mould material and help the two halves of the mould line up.