Chinese artist Ai WeiWei has drawn on the stool part of that French surrealist's pioneer work for his latest exhibition, the largest ever devoted to Ai, which opens in Berlin this Thursday. The show, entitled Evidence, is at Berlin's Martin-Gropius-Bau exhibition hall, and consists of either entirely new works, or pieces never seen in Germany before. The exhibition is huge, taking up 3,000 square metres in total and running across 18 rooms.