The latest in this annual bulletin based on research carried out at the National Gallery, London, draws on the combined expertise of scientists, conservators, and curators, bringing together a wealth of information about artists' materials, practices, and techniques. The cleaning and restoration of The Adoration of the Kings by Botticelli and Filippino Lippi reveals its unusually complex physical and attributional history. The relining of Van Dyck's equestrian portrait of Charles I is described, an operation that posed certain challenges due to its large size; at the same time the records of conservation of this painting offer a potted history of lining at the National Gallery. The recent cleaning of Jan van Eyck's Portrait of a Man ("Leal Souvenir") has shown that it retains an original surface coating that may explain its excellent condition. And finally, Leonardo's Virgin of the Rocks offers new discoveries from macro XRF scanning and hyperspectral imaging, which extend our knowledge of the evolution of the painting during its production.