The list of designers who can count Gwyneth Paltrow as a fan is not very long. Gianvito Rossi, however, is one of the lucky few. The Italian footwear scion (his father is the famed Sergio Rossi) stepped onto the fashion scene in 2006, debuting his spring collection in Milan. Several seasons—and collaborations with Joseph Altuzarra—later, Rossi has found his footing. "I always like to play with lines in a modern and organic way," he says. For fall, he paid homage to Victor Vasarely's abstract artwork, with architectural booties and op-art-print heels that would look just as good in a museum as they would on the street.