There's nothing to see here: 'Invisible' exhibition opens A gallery has gathered 50 "invisible" works by leading figures such as Andy Warhol, Yves Klein and Yoko Ono for its first show of art you cannot actually see. Exhibits at London's Hayward Gallery include an empty plinth that Warhol once stood on and a canvas of invisible ink. It says the £8-a-head exhibition shows art is about "firing the imagination," rather than simply viewing objects.