yellow rigid polyethylene sheet 2 inch thick st yellow rigid polyethylene sheet 4×8 st- Okay uhmwpe/hdpe Plastic sheets range in various thickness, sizes, and even shapes to suit the application. From 0.06 inch to 6 inches, with some custom sizes available, mmon thicknesses range from 0.25 in, 0.5 in, 0.75 in, and 1 inch up to 6 inches.