It is a resin used in architectural coatings that has exceptional weathering characteristics. PVDF stands for polyvinylidene fluoride. It is also known as “Kynar”, or more properly, Kynar 500. Kynar 500 is a registered trade mark of Arkema Inc. North America, Inc. To quote Arkema: “Kynar polyvinylidene fluoride (PVDF) resin is one of the most stable and pure of all commercial resins. It resists strong acids, solvents, and reducing agents and is used in several industries, including electrical and electronic manufacturing, chemical processing, pulp and paper, and transportation.” For more information about PVDF coatings, please refer to kynar.html