Plastic Sheets Seiler Plastics To provide you with high-quality yet st-effective plastic sheet options that meet your design specifications, we can nvert extruded plastic sheets into mpleted products such as die-cut plastic sheets, molded polyethylene sheets, and 4×8 (48”x96”) plastics sheets, through state-of-the-art sheet fabricating technology such as: 1″ x 48″ x 96″ HDPE