The Telegraph has a terrific article about the preservation and study of renowned artists' paint palettes: Why preserve Van Gogh's palette? Why preserve an artist's palette? The daubs of raw pigment or the mixes left in position can be an intriguing index to the working method and the mind of the artist. And most, once the status of art had been elevated above the realms of mere craft, would paint themselves palette in hand. Where and how colour is laid can convey emotion, psychology, religious significance. "The whole value of what you are about" wrote John Ruskin in his Elements of Drawing, first published in 1857 "depends on colour. If the colour is wrong, everything is wrong: just as, if you are singing,...