1. It has not yet been determined whether the following list refers to watercolours or oil paints. Van Gogh used both types of paint in Drenthe; but judging by the number of tubes, this order was most likely for oil paints. It is interesting that the list includes indigo, since the presence of this colour in his palette had previously been established only from June 1884 onwards – about nine months later. See letter 450, and cf. Carlo Derkert, ‘Theory and practice in van Gogh’s Dutch painting’, Konsthistorisk Tidskrift 15 (1946) 3-4, p. 99.