Together with Tony Hendrik, Karin Hartmann wrote one hit after another for their co-owned Coconut Records label. Most of all, they discovered and developed the careers of musicians who are now a fixed part of the German music scene. These include Wolfgang "Wolle" Petry, Andreas Martin, Bad Boys Blue, Haddaway, Soultans, Chypnotic, A La Carte and many others. In addition to her work on the production side, she is responsible for almost all the texts.

Fifteen million records sold, 90 chart placings in Germany, Switzerland and Austria, and over 100 worldwide. Now Karin makes 100% use of all her experience as the managing director of Hartmann Blue Ink.