Here we can see the vacuum for master, it's mold, and two "pulls" in clear plastic. Jon (the Techshop Vacuum Forming Instructor) was kind enough to allow me to horn in on his class and make these two tests during class! Talk about convenient.
Obviously, these test runs reveal more work to be done... the master, or Plug as it is referred to in the vacuum forming circles, is poorly vented (meaning not at all) thus none of the detail I worked so hard to achieve is coming through.
Still, I find these a good start. The look human and are very tough. this grade of common PETG plastic will hold up well for sculpting over.
All I need to do is cast a NEW version of the Vacuum Form Master with tiny holes near the eye sockets and maybe under the nose.
I may use a rubber/ceramic hybrid master, as an outer layer of rubber would be nice for removal after vacuum forming... one can take advantage of under cuts, vertical walls and other difficult vacuum forming issues using this concept.