Amazon.com : 30 Pack White Foam Core Board 20 x 30 Inch Foam Core Backing Board Sheet 3/16 Inch Thickness Polystyrene Poster Board for Presentations, Signboards, Arts and Crafts, Framing, Display, Projects : Office Products
Amazon.com : CreGear Foam Board 20 x 30 x 3/16", 15 Pack White Poster Board Lightweight Signboard Foamboard for Crafts, Framing, Art, Display, Presentation : Office Products
Office Depot Brand Foam Boards 20 x 30 White Pack Of 3 - Office Depot
Pacon Acid-Free Foam Board, 20 x 30 Inches, 3/16 Inch Thickness, White, Pack of 10 - Walmart.com