One of the biggest mark-ups at last week’s Old Master sales was achieved by the seemingly minor change in cataloguing of a Madonna and Family painting from “Studio of Botticelli” to “Botticelli and Studio”. The latter implies that Botticelli had a hand in it, whereas the former suggests it is the work of studio assistants. Sotheby’s took an infrared picture of the under drawing to support its view.

As a result, the painting that sold at Christie’s in 2009 for $152,000 now sold for $1.3 million. All was not quite so clear-cut in a painting almost unanimously accepted as a work by van Dyck. A rare early religious painting, The Tribute Money – long held by the Dukes of Grafton and acknowledged as autograph by the leading van Dyck expert, Dr Susan Barnes – was on offer with a $2 million estimate.

However, a short while before the sales, the attribution was disputed by the art investigation consultant Dr Susan Grundy, who claimed it was either a faked copy or an early work by Gainsborough. How much this had to do with the failure of the painting to sell is not known, but it can’t have helped.

— Colin Gleadell, The Telegraph