Check the listing for details. Core Mat 2 mil - Sold by the yard. Condition: New – Open box. Listed at 12.00 USD. Coremat is a versatile polyester nonwoven material with microspheres that is perfect for adding strength and durability to fiber reinforced laminates. It can be used as a thin core or print blocker in the manufacturing process, making it ideal for a variety of composite parts such as decks, hulls, hatch covers, steering consoles, shower cabinets, and chairs. Coremat is also commonly used as a core material in decks and hulls, as well as a print barrier in hull sides. It is designed to be fully impregnated with resin, and the microspheres help prevent excessive resin up-take.