Details 321 showed the waistline of Goya's Colossus (1808-10) - a gigantic effect achieved simply by reversing the positions of figure and background. It's in the Prado, Madrid.
The first three correct entries drawn were from: John Gash of Aberdeen; Dennis Thompson of Bournemouth; and Mary Milwright of Ely, Cambs. Congratulations all round.
Each will receive a bottle of champagne, as will this week's winners. Answers on a postcard (to arrive by Wednesday 19 February) to: DETAILS 323, Arts Desk, IoS, 1 Canada Square, Canary Wharf, London E14 5DL.Reuse content