An interesting case of a collaboration between multiple Golden Age painters is the "Portrait of Willem van Wyttenhorst". No less than four painters had a hand in its creation: Bartholomeus van der Helst, Cornelis van Poelenburgh, Jan Both and Jacob Duck. Van der Helst was responsible for the general composition and Jan Both for the landscape. It is possible that Duck painted the harness as he was a specialist in guardroom scenes (also called 'kortegards'), which depicted soldiers at leisure among their weapons, harnesses and other military gear in a guardroom. It is likely that van der Helst also painted the face but the role of van Poelenburgh is not clear.