Pat McGrath is the most influential makeup artist in the world, and in one season does over 27 major shows from Dior to Gucci. Here's our exclusive look at Pat in action backstage and find out why all the top models and designers love her. Featuring Lily Donaldson, Chanel Iman, Raquel Zimmerman Stella McCartney, Marc Jacobs, John Galliano, Alber Elbaz and Oliver Theyskens.