If stupid people wore signs so you wouldn't rely on them -- as suggested by comedian Bill Engvall -- Coroplast would be a household name. The company is North America's largest manufacturer of corrugated plastic sheet for sign substrate and returnable packaging markets. Its lineup touts a range of colors, graphics, and additives for flame resistance, UV protection, corrosive inhibitors, and other functional buffers. Coroplast caters to blue chip customers through a network of independent distributors. Exxon tapped the line to supply its name change from Esso/Humble Oil at stations across North America. Coroplast is a division of Great Pacific Enterprises, a US subsidiary of Canadian giant Jim Pattison Group.