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
PLASKOLITE 0.157-in T x 30-in W x 36-in L White Corrugated Plastic Sheet in the Polycarbonate & Acrylic Sheets department at Lowes.com
Amazon.com: (10 Pack) Black Corrugated Plastic Sheet 24" X 36" Horizontal : Industrial & Scientific