This late Twombly from 2006 was sold by Phillips in 2011 for $9m, a hefty sum for a late work when before the artist’s prices began to rise dramatically. Now, after a public and private sale of early blackboard paintings for $60+m and the appearance of another blackboard in the same range this Fall at Sotheby’s in New York, Phillips has gone back to the buyer and procured the painting for its Frieze sale with an estimate of  £8-12m (effectively priced at 50% more in four years.)

Cy Twombly, Untitled (8-12m GBP)