STYROFOAM R-4, 0.78-in x 4-ft x 8-ft Residential Sheathing Faced Polystyrene Board Insulation in the Board Insulation department at Lowes.com
Amazon.com: 30 Pack Black Foam Boards 8inx10in, HommyPrefer 3/16 Inch Thick Black Foam Board Sheet, Craft Poster Boards Foam Core Board for Projects, Photo Framing, Art Display : Arts, Crafts & Sewing
Amazon.com: Foam Insulation Neoprene Sheets with Adhesive,Multi-Function Soundproof Large Marine Closed Cell Neoprene Rubber Roll (W:12 Inch T:1/8 Inch L:59 Inch,Black) : Industrial & Scientific