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
4mm White Corrugated 48" x 96" | Cut-To-Size | ShapesPlastics
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