• Off the grid: a messier side to Mondrian
• Picasso’s obsession with El Greco
• An interview with Isaac Julien
• How Gio Ponti jazzed up Padua
Plus: William Kent’s heavenly ceilings, New York’s terrible new skyscrapers, the market’s obsession with young painters, the artists who channel their inner child, and reviews of Walter Sickert, Raphael and Winslow Homer
What happens when an artist wants to be anonymous?
An Austrian museum is hosting a show by an unnamed artist – but perhaps this act of secrecy will help us see the work more clearly