<p>The only clue to Jean Paul Mangin's true identity is hiding in his art. Unlike everything else about the elusive French sculptor, the material he works with is right there for anyone to see — giant, flat sheets of plastic, in vivid colours and glossy finishes.  Perhaps if reporter Julia Bergin can find out where they're coming from, she can find him too. And it’s that trail that leads her to a noisy factory floor, where another artist has been making strikingly similar work for years. </p>