3/8 inch hdpe sheets Manufacturer-HDPE 4×8 polyethylene sheet 3/8 x 4 x 8 HDPE Panel at OKAY. 3/8 x 4 x 8 Black HDPE Panel. 3/8 x 4 x 8 Black HDPE Panel. Model Number: BLKHDPE48X96X330 OKAY : 1295065. Final Price: $169.09. You Save $20.90 with Mail-In Rebate. More Information. Recycled HDPE Sheet Supplier []