Mom-to-be Anne Hathaway arrived to the Vanity Fair afterparty wearing a long-sleeve black-and-gold embellished Naeem Khan caftan. And celebrity hairstylist Anh Co Tran for L’Oréal Professionnel helped her play up the exotic glamour of the gown with a long, slightly undone braid. But wait, the actress has shoulder-length hair. How did she go from short bob to a waist-length plait? Luckily, Co Tran spilled all of the details on the do, exclusively with PeopleStyle.

To get the braided style, the hair pro sprayed L’Oréal Professionnel Next Day Hair from the roots to the ends to prime the star’s strands for extensions. Next, he added in extra length via several inches of extensions.

Anh Co Tran then took a section of hair horizontally from the crown to the top of both ears, creating two separate sections and pulling each into its own ponytail. With the top half, he then twisted in an “inverted French braid” to the bottom of the ponytail, repeated the same process with the second half and connected the two plaits together and secured with an elastic. The hair pro then sprayed in L’Oréal Professionnel Crépage de Chignon to give the style a “gritty texture,” and sealed the look with L’Oréal Professionnel Fix Design Spray for hold.