Coroplast Board - Natural - 3/16 inch thick - various sizes – Falken Design
Amazon.com : Corrugated Plastic Sheet for Indoor and Outdoor Use - 3/16 Inch Thick Poster Board, 24x36 Inches - Pack of 2 Black Plastic Board Sheets - Waterproof Coroplast Sheets and Lightweight
Coroplast Sign Printing San Francisco - Corrogated Plastic Boards San Francisco
Buy White 4mm Corrugated Plastic Board - 10pk
Amazon.com : Corrugated Plastic Sheet for Indoor and Outdoor Use - 4 Mm Thick Poster Board, 24x36 Inches - Pack of 2 White Plastic Board Sheets - Waterproof Coroplast Sheets and Lightweight