We R Memory Keepers Mold Press Polymer Clay

With certain shapes, the plastic may wrap around
it, locking the object in the plastic. This is called
an undercut. Polymer clay can be used to fill air
pockets and prevent undercut.
With polymer clay, you can also sculpt objects to
be vacuum formed.
INCLUDES: 2 oz of polymer clay
UNDERCUT: Prevent undercuts with polymer clay, or sculpt shapes to vacuum form