Olsen Twins x Vogue's best dressed

They have always been in vogue, but twin actresses and clothing designers Mary Kate and Ashley Olsen are now truly in Vogue, gracing the cover of the U.S. magazine's newest best dressed supplement.

The popular issue, which hits newsstands next week, puts its spotlight on ten global sister acts from British royalty, the Duchess of Cambridge Kate Middleton and her sister Pippa, to celebrity singers Beyoncé and Solange Knowles.

Also getting special mention are the French Courtin-Clarin foursome, granddaughters of Clarins cosmetics company founder, Jacques Courtin-Clarin.