Product Description. Marine Board HDPE (High Density Polyethylene) Plastic Sheet 1/4" x 12" x 24" Black lor Textured. High density polyethylene (HDPE) is used in a variety of applications and industries where excellent impact resistance, high tensile strength, low moisture HENAN OKAYorption and chemical- and rrosion-resistance properties are required. High density polyethylene is harder than low density polyethylene and has higher tensile strength, and better mpressive strength.