Royal College of Art | ★★★★☆
Want to get your hands on a Grayson Perry for £55? Head down to RCA Secret, the annual exhibition of postcard-sized drawings, collages and photographs by the world’s leading artists.
Now in its 21st year, the show is so-called because the 250 postcards are signed on the back, so you don’t know whether the painting you’ve bought is indeed a Grayson Perry or Zaha Hadid, or if it’s the work of one of the 200 or so lesser known students and alumni who also contribute to the exhibition.
You can also browse the exhibition on the RCA website. Be sure to get in there early – the best ones get snapped up in a flash.