Portrait of Jan Willemsz van der Pluym

This oval panel is barely 21 centimetres tall, and the Rijksmuseum counts it and its companion, a portrait of his wife, as the smallest formal portraits Rembrandt ever made. The sitter was close to family. In 1624 Jan Willemsz van der Pluym's son Dominicus had married a cousin of the painter's, and a grandson, Karel, is thought to have trained in his studio. Van der Pluym came from a line of prosperous slaters and plumbers in Leiden, and when he died he left 15 houses. The cropped grey head and the stiff white ruff are painted quickly and loosely, far more freely than the portraits made for strangers, which is why the museum suggests these were a personal favour. On one side of the head Rembrandt wrote the old man's age, 69, and on the other his own name and the year 1635.