(Cover) - EN Star Style - Natalie Portman considers costume a fundamental part of building a character in movies.

The 29-year-old actress received the best actress in a drama prize for her portrayal of ballerina Nina Sayers in the thriller Black Swan at last nights Golden Globe Awards.

The beautiful star thinks her ability to get into character for the film was assisted by the wonderful costumes she got to wear, and confesses she truly felt transformed when she was on set.

Clothes make all that aspect of building a character... they really help you get in because you look in the mirror and you see a different person, she told Cover Media.

Sibling design duo Laura and Kate Mulleavy of Rodarte worked on accomplishing Natalies edgy ballet style in the movie, and she admits they were particularly important in helping her transform herself. The elaborate costumes Natalie wore made the actress feel she truly had become a swan.

The costumes were really, really incredible. Kate and Laura Mulleavy of Rodarte did the ballet costumes, they were magnificent and really did help me feel swan like and they also did all the head pieces and even from the beginning they made those knit scarves, so from the beginning there was this very, like, featherlike suggestion of swanness, she explained.

Black Swan is released in the UK on January 21. (C) Cover Media