Weekend reading from Alastair Sooke's commentary on Pop Art. In 2015, Roy Lichtenstein’s comic book-style painting of a nurse fetched $95.4 million at Christie’s, an auction record for the Pop artist. Also in the same year, Andy Warhol’s painting of a dollar bill fetched£20.9 million at Sotherby's. The immense value the art world, and indeed its wealthy buyers, placed on pop artists is incredible. Perhaps what is more incredible is that there was a time when Pop Art caused pa