Type I Polyester - Plasti-Grit® Plastic Blast Media is a soft abrasive grit effective for paint stripping and blasting composites, plastics and fiberglass. Blasting with Polyester is also used for deflashing electrical components without damaging delicate parts. Polyester is the softest plastic media type. Type I meeets the requirements of Mil-Spec MIL-P-85891A and is approved for use by the U.S> Army, Navy and Air Force. Industries include: electronics and paint & coatings.