Natalie Portman needed costumes to get into character on 'Black Swan'.

The Hollywood beauty - who was yesterday nominated for a BAFTA for her performance in the film about a psychologically-troubled ballerina - admits the Rodarte-designed outfits helped her get into the role because they gave her immediate feedback on her looks.

She told BANG Showbiz: "The costumes were really, really incredible. Rodarte did the ballet costumes. They were magnificent and really did help me feel swan-like.

"Even from the beginning they made those knit-scarves so that from the beginning there was this feather-like suggestion of swan-ness from the start of the film. Clothes, make-up, all of that sort of aspect of a character really help you get into... you look in the mirror and you see a different person. You get that feedback."

The actress has previously discussed how hard it was to get into the character of self-punishing dancer Nina, and Natalie has revealed she discovered a lot about herself.

She said: "I suppose I learnt how much I could do. I think of myself as someone who seeks pleasure and doesn't like pain to actually put myself through pain for that long and not just make myself feel good was I guess a scary thing to discover.

"But it was also good to know I could focus in that way for a role. It's frightening to know you can deprive yourself in that way."

'Black Swan' has already been released in US cinemas and comes to the UK on January 21.