Paul Marciano has been an innovator in fashion campaigning since launching Guess in 1981. During that time, when the fashion advertisements were bright and colorful, Marciano turned his Guess ads black-and-white. In the '90s when the rest of the fashion world was featuring the infamously thin Kate Moss, Marciano made curvaceous Anna Nicole Smith his new Guess Girl. And just recently, instead of taking in a slew of new models, Marciano rehired veteran Claudia Schiffer for his ads.

How is it that Marciano has made his Guess campaigns so idiosyncratic, and yet managed to be so successful? Marciano recently told Women's Wear Daily that it's his talent: those famous Guess Girls who have captivated the masses since day one.

So, what exactly does it take to be a Guess Girl? Marciano says looking "healthy" is a big part of it:

"Since the day we started Guess, the brand has always stood for young, sexy and adventurous, and it is these same qualities that I look for in the models that become Guess Girls. They also have to look healthy. When the waif look first came into fashion, Anna Nicole Smith was in the Guess campaigns looking like a real woman. A girl who looks too thin and unhealthy does not look sexy to me, and she does not look right for Guess."

Smith was just one of the girls whose careers took off after modeling for Guess. Marciano was also a part of launching Claudia Schiffer and Ellen von Unwerth to new heights. But there is one Guess Girl whose career Marciano doesn't take responsibility for:

"I wish I could say that Carla Bruni’s Guess campaign at age 16 led to her current role as First Lady of France, but that might be a stretch."

Click through to see some of Marciano's most successful Guess campaigns and head over to WWD to read more about the designer.

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