Not just a pretty face

There are two types of beautiful actress. Type A will embrace fame, and dutifully expose important parts of herself in magazines and at premieres. The first time she is cast as a mother, she will know the bell tolls for her career. Type B is a character actress trapped in the body of a temptress. Ambivalent about her looks, she doesn't see herself as a celeb, and Chinese water torture would not tempt her to discuss her boyfriends in print.

Catherine McCormack is a Type B. She has sharp green Celtic eyes, an orthodontically perfect smile, and all the bone structure you could wish for: Forties Hollywood cameramen would have sprung out of bed to light her proud jawline. But six years on, that big-break role in Braveheart now looks like a massive red herring. McCormack played Murron, Mel Gibson's peasant bride, a coy virgin on heat in the peaty Scottish mist. She was a sort of Montessori-era Diana Spencer transplanted to the medieval Highlands.

Spool forward to the present. In the intervening period she's lent her burgeoning bankability to any number of ensemble chick flicks; lately, she has edged her way across into the theatre, and earned an Olivier nomination for her part in All My Sons last year. Not yet 30, McCormack now seems to be trying to put the droolers off her scent.

You may not have seen Born Romantic, a three-couple comedy that performed a ghostly flit across our screens this spring. McCormack was wrapped into a huge foam neck brace, and walled in behind a grotesque pair of glasses. She was physically awkward and spoke in a high-pitched squeak. Braveheart wouldn't have looked at her once, let alone twice.

And now, at the Donmar Warehouse, she's in A Lie of the Mind, the 1985 play by Sam Shepard. She plays Beth, a woman who has been beaten by her husband into vocal incoherence and physical near-paralysis. She can't walk or talk straight, she's tattooed in bruises, and when McCormack explains how she's researching the part ? by visiting a rehabilitation clinic for stroke victims ? the words intuitively slide out of the side of her mouth, like a stroke victim's. 'Oh, I'm such a method actress,' she says.

Anyway, she won't be looking her best in this one. It's as if she's on a mission to erase the evidence of her own photogenicity. I'm not alone in thinking this. 'When he saw Born Romantic, that's what my dad thought, too. He was devastated. But it's more about getting interesting roles. You still get those parts where you don't want to deface yourself and you want to look as good as you can, be a strong, powerful, beautiful woman. But it's just to do with the parts. When I read scripts, there's always a lot of "she's got long, dark hair". It's this fantasy image of a woman. I know what it's going to say next. It's going to say, "All the men dropped dead when she walked in the room." It's not to do with me.'

So, this notional woman is basically Elizabeth Hurley? 'Exactly.' A Type A.

So if this dream woman is nothing to do with McCormack, what is? We met in a caf? in Richmond. She was there before me, so there was no opportunity to drop dead when she walked in. She owns a top-floor flat in a Georgian house round the corner. McCormack chose to live in Richmond because, as she says, 'it's quiet, and it's by the river, which I love. I'm up by Mick Jagger's house. Not that I know him.'

I met a shyer incarnation of McCormack three years ago. In the intervening period she seems to have grown a hard outer crust to deal with occasions such as this. Even her voice seems deeper, though that may be the smoking (four in 90 minutes). You can tell by the number of lunchtime snackers who recognise her (none) that she is not a celebrity. I don't recall seeing paparazzi shots of her and Joseph Fiennes when they were an item, and I bet she made sure there weren't any. She seems contentedly allergic to that milieu. I don't think it's mere affectation that in conversation she forgets the names of famous co-stars (including Hurley's; they are both in a film due out this autumn called The Weight of Water). She mentions how all actresses have an image, and hers is 'a bit untidy, with awkward shoulders'. She gestures at her baggy white linen shirt. At school she was always playing 'Mrs Overall characters'.

'People meet you and think you're going to be a stunner,' she says. 'They all expect you'll turn up like Murron from Braveheart, which was all about long hair and clean make-up and an image of an earthy, beautiful woman. Most people, if they donned a beautiful frock and raised things up and did their hair, can look attractive.' Then she adds, 'My dad wants me to dress up more.' Her father, now retired from the steel business, brought up her and her older brother after their mother died when Catherine was six. 'He is the most important person in my life, bar none. He's a very good man.' It was the thought that 'the family will love it' which persuaded her to suppress a shudder ? and the memory of a shoot she once did in a bikini with a fag hanging out of her mouth ? and submit herself to a stylist for this ES photo session.

The immediate aftermath of Braveheart was the title role in a film called Honest Courtesan. Set in 16th-century Venice, it was shot in Rome. The star got a Roman flat with a roof terrace for a month, and didn't have to do her own sex scenes (unlike co-star Rufus Sewell). She got to fence. But somewhere in post-production, the film's name changed to Dangerous Beauty. Can she remember her sensation on first seeing the final cut? 'I can. Let's just leave it at that.' She goes on anyway. 'You never know what things are going to turn into. I know more now, but I didn't so much then. The story behind it was fantastic, but yeah, in the hands of someone else it may have been darker and more interesting.' Venice is still sinking. The movie sank at once.