October 27 sees the opening of a major and scholarly exhibition at the National Gallery, London. Images have been retrieved from the underdrawings to major oil and tempera works by Raphael, Brueghel and Cranach the Elder, and Carlo Crevelli, as well as Jacopo Pontormo and Cosimo Tura in particular. The exhibition reveals secrets in technique only guessed at until recently. The exhibition is sponsored by GlaxoSmithKline and offers free entry. Forgers beware technology sees all.