Misattribution. Gouache, signed both Karel and Constant, year unknown. Found in the estate (including a suitcase with drawing pads and pencils) of former policy officer at the Technical University of Twenthe and painter Karel Levisson (1917-1999). We assume this was a portrait by Karel (hence his signature, bottom left) of a man called Constant (bottom right), not Constant Nieuwenhuys (1920-2005).