Blank art canvas expected to sell for over $1.5 million

A blank canvas by Robert Ryman, titled General 52" x 52", will be up for bidding at a Berlin auction this week. Valued at over $1.5 million, it's painted in white enamel and enamelac paints. The material is so delicate that it could not travel to be on view ahead of the sale, said the auction house.