A barren white canvas, valued at more than $1.5 million, is up for auction in Germany this week. The 1970 piece by minimalist American painter Robert Ryman — titled "General 52" x 52"," a nod to ...

Artist Andy Warhol's iconic black-and-white painting of a Coke bottle hits the auction block at Christie's on Tuesday. It is expected to sell for more than $40 million.

Robert Ryman's 1970 piece, titled General 52" x 52", may seem like a mere white canvas at first glance, but its subtle intricacies and materiality are far from ordinary.