Vacuumforming is relatively simple fabrication process that heats sheets of plastic to a pliable state, and then pressure forms the plastic over a plug mold. For low-budget scenarios like costuming, vacuumforming can be done in your home. There is no need to go to a professional vacuum-forming shop to get parts made.
Video demo of basic vacuumforming....
Be very careful doing the things described in this section. You can get seriously injured if you do not take things slow and with precaution.