A new book argues that art copyists get a bad rap. They're not always forgers out to scam the unwary. In fact, there's an art to copying art that deserves its own place in art history. Former public art gallery curator and director Penelope Jackson is the chair of the New Zealand Art Crime Research Trust. She's delved into the history and the many reasons - legitimate and nefarious - for people to copy works of art over the centuries. Some are student artists making copies as part of their training. Some are creating props for movies. Penelope explains to Lynn Freeman why she thinks art copyists have a valid place in art history. Penelope Jackson's The Art of Copying Art is out this month, published by Palgrave Macmillan.