In which painting by which painter can you find this piece of wood?

Details 349 showed the desktop from Jacopo de Barbari's Portrait of Luca Pacioli (1495). The original is in the Museo di Capodimonte, Naples. The first three correct answers came from Elspeth Graham-Yooll of Edinburgh; Anne Holmes of Bampton, Oxon; and Barry Walsh of London SW13. Each will receive a bottle of champagne, as will this week's winners. Answers, on a postcard (to arrive by Wed 10 Sept), to: DETAILS 351, IoS, 1 Canada Sq, London E14 5DL.