Duhem was seventy when he started to draw and paint. He would always work in the same way. First of all he would cut the sheet of paper down to size with a knife, and then use a length of wood to draw a frame around the sheet. In the top left-hand corner he would write his name, also in a little frame. He had learnt to do this long ago at school. When he worked with paint, he would not use a palette, but emptied the pots into sardine tins. Because of this, his paintings have a restricted number of colors. He never washed out his brushes. The paint became mixed together, and by the time the pots were nearly empty, his work would take on an olive-brown tint. Although Duhem only started painting late in life, he left behind a large body of work. The endless repetition of the same themes gives this work a somewhat enigmatic quality. It is as though there is something that Duhem is always trying to grasp or capture.