It's not just the voice that Frances de la Tour takes for granted. She's also ('when you've been around as long as I have') grown accustomed to a certain type of theatre based like most British and American drama on the word according to Stanislavski. She's used to 'letting myself go, not to be aware of myself at all', and is inclined, it must be said, to talk of a dramatic work in terms of a 'process of discovery' (breathily, a la Miss Jones from Rising Damp) or a 'journey' to be embarked upon with the lofty doggedness of a board-treading Ranulph Fiennes.
But it's possible that De la Tour has grown tired of reciting the party lines: she's already broken convention by playing Hamlet (at the Half Moon); she talks of 'universal themes' with a lopsidedly ironic smile; and her latest project, a one- woman play, has even taken her on a real journey - to Tokyo - and into contact with strange theatrical beings: a Japanese playwright, Hisashi Inoue, a 'modern' Japanese acting troupe, the Chijinkai Theatre Company, a Japanese director, Koichi Kimura, and quantities of thick plaster-like Japanese stage make-up. 'It really gets into the pores,' she says.
The play is called Greasepaint and centres on the tough actress-manager of an Engeki theatre company - the lower-grade 'music hall' relation of Kabuki. De la Tour is alone on stage throughout, preparing for her role as a young warrior - wrapping herself in traditional wig and robes, rehearsing certain movements, taking on and off a great deal of make-up (without mirror). She deploys stylised Kabuki gestures - in which 'the girls turn their feet and walk with their knees together; the man always stands with one foot in front of the other - very heroic, very bold'. But she manages to do so in an oddly naturalistic manner: her character taps his / her stomach a lot and feels along the waistband - it's a conventional Kabuki statement of masculinity, but De la Tour adds a falter of insecurity. The play's about the world of Engeki, but she makes clear it's also about peeling back layers of disguise and self-deception - 'about the face behind the mask'.
Backstage at the Lyric Hammersmith the actress is scrubbing away at layers of paint and powder and greasy wax ('very important though nobody sees it; it keeps the make-up on and stops you from sweating through'). She's wiping great swathes of cotton wool across her face, stretching and twisting her flesh as if manipulating it back into shape. 'It's not putting it on that's difficult,' she says into the mirror, her mouth looped to one side, 'I don't know about you but I've often made up in taxis - although I've no idea what I'm doing with those eyebrows . . .
'No, it's having to do it while doing other things. Having to speak and do at the same time. It sounds so ordinary, because we do it in life the whole time, but when you have a learnt script it is very difficult to train your mind to be that exact. I found that really hard and it got very pedantic - it was like 'blue goes on . . .' ' She points to a huge photocopied page of the script pinned up on the wall behind her in which her speech is annotated with 'powder' / 'face' / 'legs', and grimaces. 'But actually you can't do it on the word, which is the kind of discipline I need, because you never know exactly how long it's going to take. It's going to have to be improvised a bit every night.'
The make-up is only one of the stumbling blocks: she's also thrown a small distance every night by her costume. It's instilled in her a 'terrible fear' of drying: 'Like last night, it was just because I hadn't tied something up - there's a corner of your mind that's thinking about the feel of the string or where it's going . . . and then you've missed the next line.' She's also disturbed by the loneliness of the one-woman format. 'It's a hell of a thing to carry. I love acting with other actors, catching their eyes. Here, I've got no one to refer to. I keep wondering, 'How am I getting on? Am I losing it?' '
But, none of this, she insists, measures up to the most difficult part of the play: 'Which is the same as any play really. Who is this woman and how do I get to her depths? How do I get to her highs? The director and I did have trouble communicating initially. Women behave in a very particular way in Japan, but if you say 'yes, but in this play she wouldn't,' they have great difficulty with that. I think understanding my way of reaching things was hard for him. For example he suggested I showed anger at one point, followed by great pain; for him it was a technical matter. And I said, 'Well yes, but I don't know until I go through the process'. The important thing is to make it look natural - so that if you watch Torvill and Dean skate, you think they're not on skates, they just having a ball out there. And it's the same with Kabuki.'
Later this year, Frances de la Tour will be appearing in a new comedy series, Every Silver Lining, as one half of a diner-owning married couple. Will anything that she's learnt here inform the way she approaches her next job? 'Will what, darling? Will what?' she says. 'Oh, goodness no. Switch off straight away - instant death. Certainly no make-up tips.'
'Greasepaint' runs until 6 March at the Lyric Hammersmith, King Street, London W6 (Box office: 081-741 2311).