A prolific artist, it's not terribly difficult to track down an original Picasso sketch. Yet none of those will offer a clue as to how he worked like the palettes on which he mixed his hues. As part of a larger auction offering a wide range of Picasso's work, these palettes were used by the Cubist master himself. Three total are available, including two traditional wooden palettes used in 1973, as well as a piece of cardboard used in the early 1960s. All three have remnants of Picasso's oil paint mixtures still visible and have been confirmed as authentic by Claude Picasso, the artist's son, and hail from the estate of Marina Picasso, his granddaughter.