Jan Holtrup took up painting relatively late, at the age of 42. He moved to Hilversum to take lessons from the landscape painter J.F.C. Scherrewitz, whose work was strongly influenced by the Hague School. Holtrup's preferred subject matter was the countryside in the Veluwe, Gooi and Brabant regions. His style remained close to that of his teacher, albeit more subdued, occasionally verging on romantic. In the 1960s he took his work farther afield to the Oosterbeek region. Holtrup also painted landscapes in Germany and Austria.