ProMark Poly Signs are manufactured from specially formulated (HDPE) High Density Polyethylene with UV inhibitors.  ProMark Poly Signs are specially designed to repel to chemicals, solvents, stress cracking, and other forms of wear and tear, unlike conventional aluminum and metal signs which hold on to weathering and outside damage. ProMark Poly Signs are manufactured so that graffiti and spray paint can easily be removed.  Poly Signs can be manufactured in different sizes and color options to guarantee the most effective protection to any underground utility.