Thomas Kortmann makes custom guitars in Oberursel, Germany. Kortmann is best known for his Les Paul style electric solid bodies. In 1981 Kortmann and Rolf Bingenheimer set up Bingenheimer & Kortmann (B&K), which was a music store and guitar workshop in Oberursel. B&K made custom instruments: both acoustic and electric guitars & basses.

Source: Kortmann Custom Guitars website (21 November 2017)