Painted on his birthday July 21st, 1949, this painting captures the heartache Constant experiences after his wife Matie has left him for his friend and colleague Asger Jorn, taking his two daughters Martha and Olga with her.

A drawing on a page from one of the notebooks of his wife at the time, Matie van Domselaer, who was studying ancient languages.

A small printed booklet with poetry by Gerrit Kouwenaar and drawings by Constant. They created it in 1949 and it was supposed to be a little joke. This is also one of the lines in the booklet: 'Everyone considers themself to be a joke, A joke is allowed' The words and drawings are an expression of the playfullness of their creators where sometimes the words came first and the drawings followed as a reaction and sometimes the other way around.

A small printed booklet with poetry by Gerrit Kouwenaar and drawings by Constant. Kouwenaar was a member of the Dutch poetry group known as the 'Vijftigers,' which had close ties to the CoBrA movement. They created it in 1949 and it was supposed to be a little joke. This is also one of the lines in the booklet: 'Everyone considers themself to be a joke. A joke is allowed' The words and drawings are an expression of the playfullness of their creators where sometimes the words came first and the drawings followed as a reaction and sometimes the other way around.