Knauf

Knauf is an multinational, family-owned company based in Iphofen, Germany well known for drywall gypsum boards, originally founded in 1932. The company is a producer of building materials and construction systems comprising construction materials for drywall construction, plasterboard, cement boards, mineral fibre acoustic boards, dry mortars with gypsum for internal plaster and cement-based external plaster and insulating materials; glass wool, stone wool and other insulation materials under the company Knauf Insulation. It has more than 150 production sites worldwide.[1] It is one of the seven producers which hold approximately 81% of the worldwide wallboard market (Georgia Pacific, Knauf, Siniat, National Gypsum Company, Saint-Gobain, U.S. Gypsum and Yoshino Gypsum Co.

source: wikipedia