Amazon.com : Excelsis Design 15 Pack Foam Board 24x36 Inches | Black Foam Board 3/16 Inch Thick Black Core Mat | Backing Board for Presentations, Signboards, Arts, Display and Crafts with Double-Sided
Elmer's Foam Board 3/16" X 24" X 36" Black-on-black 81242 : Target
Foam Core Backing Board 3/8" White 24x36- 25 Pack. Many Sizes Available. Acid Free Buffered Craft Poster Board for Signs, Presentations, School, Office and Art Projects - Walmart.com