Polypropylene is a low cost, chemical resistant plastic with excellent aesthetic qualities. It is easy to weld using thermoplastic welding equipment and is often fabricated into water and chemical tanks. Polypropylene used in the manufacturing of upper and lower extremity orthoses and prosthetics offers the O&P fabricator a material that is easy to drape, blister form and seam. Polypropylene is easy to decorate with transfer patterns for O&P applications.