Expanded PVC Foam Board, White, 1/32" (0.078", 2 MM) Thick, 12" w x 12" L (Pack of 8): Amazon.com: Industrial & Scientific
Amazon.com: 1 Inch Thick Foam Board Sheets - 6 Pack 17x11 Inch Polystyrene Rectangles for DIY Crafts, Insulation, Sculptures, Models (White) : Arts, Crafts & Sewing
Amazon.com: AMZQNART Craft Foam Blocks, 1 in Thick 17x11" EPS Polystyrene Rectangle Foam Blocks Packs of 7 Pcs for Art Sculpting, Sculpture, Modeling, School and Home DIY. : Arts, Crafts & Sewing
Expanded PVC, Foam Board, White, 1 MM (0.04") Thick, 12" W x 42" L (Pack of 4) | eBay