Books are enormously complex creations, and clearing them of errors takes the immense, repeated effort of editors and proofreaders. Proofreaders are unsung heroes, who often work best with pencil and coloured pens, and a stack of publishing reference books. Today, they’re often asked to mark up corrections on screen in PDF – but is that really best? In this episode, Arthur talks about that with editor and entrepreneur John Pettigrew, the founder of Futureproofs. How can we innovate in this part of the publishing process? And what lessons can we learn here about innovation in publishing more broadly?