(CNN) — In 1958, artist Yves Klein famously opened an exhibition called “The Void,” which saw him place a large cabinet in an otherwise empty room. Thousands of paying visitors turned up at a Paris ...

Art lovers were left to stare blankly after a receipt for a piece of “invisible art” sold for nearly $1.2 million at auction. The receipt, dated Dec. 7, 1959, was part of Klein’s imaginary art series ...

In 1958, artist Yves Klein famously opened an exhibition called "The Void," which saw him place a large cabinet in an otherwise empty room. Thousands of paying visitors turned up at a Paris gallery to ...

In 1958, artist Yves Klein famously opened an exhibition called “The Void,” which saw him place a large cabinet in an otherwise empty room. Thousands of paying visitors turned up at a Paris gallery to ...