Amazon.com: 6 Pack White Foam Sheets 1 Inch Thick, Polystyrene Rectangle Blocks for DIY Crafts, Art Supplies, Packing (12x4 Inches) : Arts, Crafts & Sewing
Polystyrene Foam 24"x48" Sheet | Foam Factory, Inc.
Amazon.com : AKOLAFE 30 Pack 10x8 Inch Foam Boards, 5 mm Thick Foam Core Board 1/5 Inch White Foam Sheet, White Polystyrene Poster Board Signboard for Presentations, School, Office & Art Projects : Office Products