When I first started out, I was very idealistic. I thought that all people cared about was that the acting was good and you transformed into the character. Iīm fascinated with pretending to be other people and imagining what other peopleīs experiences might be like. I played with the dressing-up box a lot when I was young - donīt all kids? The character
I play in Armadillo, Lorimer Black, has the same fascination. Heīs chameleonic, like an actor. Itīs almost like heīs a private eye whoīs permanently under cover and shifting shape. The whole idea of deception and disguise is something that you take into your acting. You canīt over-dramatise it or it becomes too flamboyant and theatrical. Itīs the subtle changes that we all manage all the time that you tap into.
When you're playing a role, how you make yourself look on the outside is about reassuring yourself, making yourself feel safe. I lost a lot of weight when I played the title role in Vigo [in Julien Temple's film of the life of Jean Vigo].
I wouldn't like to have to do it again, I was really skeletal. It seemed important at the time, but now it seems rather a strange thing to have done. I was a bit keen, I think. But it is more fun to change your looks in some way - it's that part of you that just likes dressing up and wants to have a wig and a beard. When you're acting, you just want to feel comfortable and confident that you're somehow magically transforming yourself. It's always vaguely depressing afterwards when you see yourself and it only ever looks like you.
I sometimes fantasise about what it would be like if I could change myself. There's a Peter Carey story called "The Chance" which was set in the future where you could go into this kind of passport booth, put money in and all your genes got rearranged. But you don't know whether you're going to get more beautiful or more ugly - it's a lottery. I might want to make myself more perfect looking, but would I still feel like me? These days, when I watch myself on screen, I see my brother or my mother in the way that my nose twists or the way my teeth gather. You can see all the genes going on and it's kind of amazing.
You don't have that much control over how you look on screen - it's dependent on the photographer, on how you're lit, how they do your hair, how they want to present you. Sometimes you turn up and they've got a very strong idea of how they want you to appear and they'll win that battle. There have been times when I've looked at stuff of mine and thought: 's**t, that looks bad'. You could get neurotic about it, but what's the point? I was working in LA for almost a year and it was quite mad because, for the most part, everyone looks astonishing. Most people are just really damn good looking. Fortunately, European actors have a sort of exotic charge - people are like, "Oh wow, you're British? You're like a real actor!" They think you've had some magic training, like you're a Jedi Knight or something. It's bulls**t of course - but no need to tell them.

`Armadilloī (adapted from the William Boyd novel), a three-part drama, begins on BBC1 on 16 September. (Copyright 2001 Independent Newspapers (UK) Limited)