PPG Industries is an American global supplier of paints, coatings, optical products, specialty materials, chemicals, glass, and fiberglass. With headquarters in Pittsburgh, Pennsylvania, PPG operates in more than 70 countries around the globe. Sales in 2012 were $15.2 billion. It is headquartered in PPG Place, a popular office and retail complex in downtown Pittsburgh, Pennsylvania, and is known for its glass facade designed by Philip Johnson. Founded in 1883 by Captain John Baptiste Ford and John Pitcairn, Jr., as the Pittsburgh Plate Glass Company at Creighton, Pennsylvania; the company changed its name to PPG Industries, Inc., on 19 December 1968 to show its diverse offerings. Ditzler Color Company, established in 1902 in Detroit as an automotive color concern, was purchased by Pittsburgh Plate Glass Company (now PPG) in 1928. In 1990 it founded and continues to operate Transitions Optical as a joint venture with Essilor. On 2 January 2008, PPG acquired the SigmaKalon Group of companies for $3.2 billion from private investment firm Bain Capital, strongly increasing its paint and specialty coatings business. On April 1, 2013 PPG completed the acquisition of AkzoNobel North American architectural coatings business including Glidden, Liquid Nails, and Flood brands.