Details competition no 437 by Tom Lubbock

Details 435, by mischance, came out more tightly cropped than it was meant to be. Consequently it was almost impossible to identify. Nor was it identified. This is the first week that Details has no winners.

It was never going to be easy, anyway. The detail came from Michiel Sweerts' presumed Self-Portrait (1656) - or alternatively his Portrait of a Man. It's a dreamy and disjointed image: the sitter's head leant right over on his hand in a "melancholy" pose; hands, cuffs and objects made into an almost free-floating arrangement of elements. The picture is used, very aptly, on the cover of the Penguin edition of Locke's Essay on Human Understanding. It's in the Hermitage, St Petersburg.

In which painting by which painter can you find this business?

Answers on a postcard, to arrive by Friday 18 June: DETAILS 437, IoS, 1 Canada Square, Canary Wharf, London E14 5DL. Three winners will each receive a bottle of champagne