Pittsburgh-based PPG is a global supplier of paints, coatings, optical products, specialty materials, chemicals, glass, and fiberglass. The company has over 140 manufacturing facilities and equity affiliates and operates in over 60 countries. Using the plating process, PPG became the first commercially successful producer in the United States of high-quality, thick flat glass. The company was the world's first plate glass plant to fuel melting furnaces with locally produced natural gas. This innovation quickly stimulated the widespread use of clean-burning gas as an industrial fuel.