The microsite for Tate's Drawing from Turner exhibition is always worth a visit, not leats because it offers an online view of some of the most exquisite paintings from Tate Britain's Turner Bequest Collection.
As the site boldly proclaims: "There is arguably no greater insight into the working techniques of a great artist than the unique collection that is the Turner Bequest..."
http://www.tate.org.uk/whats-on/tate-britain/exhibition/drawing-turner/drawing-turner-turner-bequest
