Peter Doig may be at the centre of an art world whirlwind but he's as driven as ever. Phil Miller meets the artist on the eve of his first Scottish show.

'Ah, now you are talking about the other Peter Doig," Peter Doig says, smiling. The other Peter Doig, the artist says, with a soft laugh, is not him. This Peter Doig, the artist, is sitting in this London gallery office, slightly frazzled from a transatlantic flight, ready to oversee the hanging of his new - his first - show in his homeland of Scotland. The other one, the art auction superstar, is not the weary, red-eyed Doig who has spent the past month in his studio, working 20 hours days, painting deliriously.

The doppelganger he is referring to is an acclaimed artist who grew up in Canada and is based in Trinidad, New York and Dusseldorf. He has been credited with reinvigorating the art of painting, his landscapes and ambiguous figures entrancing collectors, academics and gallerists alike. He is an outsider with a peripatetic life, a man whose elusive, sometimes enthralling painting is among the hottest properties in the art world, and whose paintings sell for millions of pounds.

Both Peter Doigs will be in Edinburgh this summer: the reflective, quietly spoken painter and the art world commodity. This Scot from the diaspora - who has never painted Scotland, who was born in Edinburgh but never lived here for any length of time - will fill the Scottish National Gallery with his debut major show here, No Foreign Lands. Doig has taken an extraordinary journey from Scotland to the world, and now back home.

His paintings - rich and layered, unnerving, beautiful, skilful, luscious, sparse, ghostly - sell for eye-popping sums. Earlier this year, his beautiful The Architect's Home In The Ravine was sold by Christie's for £6.8 million (more than $10m), and the sale in 2007 of White Canoe set a record for a living European painter. These enormous sums do not come to Doig, of course, but the collectors who sell them. And the numbers just seem unreal to him.

The son of a Scottish accountant in a shipping firm and a drama teacher, Doig has not talked about Scotland, what it means to him and his art, in great detail before. He will today. But first he groans as I ask him about the enormous sums his paintings

sell for. The success has made his life easier - "I am wealthy now," he acknowledges -

but has not distracted him from his unwavering focus: painting.

This is a painter with presence: he is tall and fit, with large hands, a shaven head and a beard. He plays rough-and-tumble ice hockey (the Montreal Canadiens are his favourite team, he also plays "pick up" hockey in New York) and once took a job as a roughneck with a crew drilling for gas on the Canadian prairies. His accent is faint but there: Canada with perhaps a hint of Edinburgh.

He sighs when I raise the cost of his paintings. "Yes," he nods, "over 20 of

my paintings have sold for over £1.5m, something crazy like that. The weird thing is that people think that is how much I am selling them for, and that I, myself, am selling them. That's crazy.

"Someone was asking me about it, and

I told them: 'That painting that sold for $10m? I sold that for £2000, and I got £1000 at the time.'"

Doig remembers his first sale: a painting he let go for £200, four weeks wages for him at the time, which seemed like a huge sum. When he sold his first painting for £10,000, he thought it was crazy, the same price as

a new car, he thought.

And now? "It's all very strange, really. The Architect's Home In The Ravine probably sold for more than that house [in the painting] is worth. When it first happened,

I thought: 'Oh my God, now I am in real trouble, I am just going to become a mockery.' It happened so quickly. I thought it might affect my work, I thought: 'How

can I possibly go into a studio and make a painting and it's going to be worth that?'"

Money may make his travelling easier, he says, but does not make his art any easier.

"I don't think money can help you become

a better painter, for sure. You can have all the studios you want, it won't help you make a better painting. You cannot just be working in a vast, air-conditioned loft space and think you are going to make a decent painting. Francis Bacon had a special studio built, and he felt completely emasculated in there. I have to be somewhere comfortable.

I want to paint."

That painting, in the past few months, has been feverish and intense. A prior interview date, in Manhattan, was cancelled because Doig was in the midst of several 20-hour days so he could finish work for the Scottish show. He says he is always good at starting, but needs a deadline to complete. He shakes his head. "It gets more and more extreme as I get older. There are weeks on end, months, where I am working nights, working nights. For the last weeks, I have slept the maximum three hours. I feel quite delirious.

"The other night, I was trying to resolve this painting, which I think I have resolved, and I thought: 'I have lost my ability to make decisions, I can't see colour any more.' You panic. You think, 'My God, what am

I going to do?'"

His life certainly hasn't been conventional. Doig spent the first year of his life in Edinburgh before his family moved to Trinidad. Then, in 1966, they moved again, to Canada. He returned to the UK, to London, in 1979 and in the early 1980s studied at Wimbledon School of Art and Central Saint Martins.

A move to Montreal followed in 1986 and, three years later, he went back to London. Then came a nomination in 1994 for the Turner Prize, a painter amid the BritArt explosion of conceptual art. He moved to Trinidad with his wife and children - he

has five - in 2002. He also spends time in Germany: he is a professor at the fine arts academy in Dusseldorf.

But Scotland is slowly but surely looming larger in his life. As a child he holidayed here many times, and he was very close

to his grandparents in Edinburgh and

St Andrews. There was even a brief, "bizarre" and unhappy time in the north-east as a boarder at a private school, which he does not want to name.

Last year, significantly, he took a holiday on Mull, whose beauty affected him deeply. He took many photographs, images which serve, often, with memory, as the key source materials for his work.

Doig speaks of the island in awe and almost surprise. "I was astounded by

how beautiful it was," he says. "The water was the colour of this [mineral water] and

I just had to go in, but it was absolutely freezing. Imagine if the water was warm

- Mull would be the most populated place

on Earth."

Will he one day paint Scotland? He seems to think he will, but you sense he does not want to be tied to the idea. He once said "finding new things to paint" is the hardest part of his working life. But that obstacle might be in the past. "When I went to Mull," he says, "I was thinking: 'I could do some paintings of this,' and at some stage I think

I probably will."

Doig pauses for reflection. "Yeah, I think

I will. I genuinely think the answer is yes, but I don't know when. I have known about Mull since I was a child - one of my dad's best friends had a place there, and I always had this idea of what it was like. I thought

it was an extraordinary place. When I

look at that, I think it is very paintable.

I photographed it a lot.

"Scotland does have a resonance for me.

I was always very aware that I was Scots, and I had a very close relationship with

my grandparents. And if I hadn't kept going back to Scotland, I think I might not have gone back to the UK when I was 19. The music scene in the 1970s … I think I got attracted to the idea of going to art

school then."

In fact, a key move for Doig was visiting Glasgow in 1979. He had heard that his cousin on his mother's side, Robert David MacDonald, ran the Citizens Theatre in the city. MacDonald, a renowned playwright and translator, had done so since 1971, and would do so until 2003 alongside Giles Havergal. Doig shipped up one day in the Gorbals unannounced and asked to see him.

Doig smiles at the memories. "He was very good to me, and we became very close. I didn't know him, but his mother was almost a surrogate grandmother to me: she had a house in Chelsea in London where I used to stay. She was a great presence in my life. But I had never met him and I just knew he ran this theatre. I ended up staying with him for weeks.

"Glasgow in 1979 felt very, very rough

to me. I hadn't seen so many men with scarred faces in my life. I remember going to see a production of Orpheus at the Citizens which was absolutely fantastic, and we went for drinks afterwards, and we went for another drink, and I remember trying to get back home from the Gorbals, and it was so desolate. It really reminded me of Buffalo in New York, a really depressed, bleak town at that time too."

But before that, I wonder, did those early summer holidays in Scotland, often in the north-east, subconsciously lead to his fascination with landscape and form? He is known for his snowy Canadian vistas and his humid, sweatily intense Trinidadian work, but perhaps Scotland's mountains and straths are lurking there too.

"It's interesting," he says. "I have spent

a lot of time in the Scottish landscape, as a child, as a youth. But when does one become influenced? I think my experience of places is part of me, and very important. Scottish landscapes, Canadian landscapes, Trinidadian landscapes - yes, the temperatures are different, but the shapes are not a million miles apart."

Doig's wanderlust runs deep, although

he emphasises it is only with his work that he has travelled widely. But he comes from

a family of travelling Scots. His father was born in Sri Lanka, his grandfather was

born in India and his great-grandfather

also worked in India.

He thinks back to his upbringing in Canada. "My parents were never really Scots in the sense that they would take part in Scottish things. They were not a Scottish clique. Yes, of course they were fond of Scotland and were deeply connected, but it wasn't their be-all and end-all. They never took part in the local Highland games."

Doig is described by the National Galleries of Scotland as "one

of the most highly regarded

and internationally renowned painters working today". I raise this point. He wonders whether he is an "international artist" at all. He says he never intended to be regarded as one, or intentionally painted to resonate across borders and cultures. He remembers his surprise when, at an early show, a Japanese woman said she could very much relate

to his work.

"When you get into specifics, there is a real art scene in Trinidad, and a great history of painting there," Doig says. "And that is like Scotland: a lot of people outside Scotland don't know the great Scottish painters. Who knows about the Scottish Colourists outside Scotland? It is like the Group of Seven in Canada. They are great Canadian painters but it doesn't really travel. A lot of really good art doesn't travel. I never tried to be an international artist,

an artist whose work was international. People have experiences with your work that you could never imagine they could possibly have.Why does certain artists'

work have an appeal outside the local?

I don't know."

Doig's show, which opens next weekend, features work from the past 12 years, including at least three new works and etchings from this year, besides a lot of material not seen in the UK before. No Foreign Lands, after it has been shown in Edinburgh, will be shown at the Museum

of Fine Arts in Montreal.

"I am really pleased they wanted to focus on work from 2000," he says, "because a lot of the well-known work, if you like, seems to be from the 1990s, and I was pleased they were prepared to make it more current."

His long-time friend and neighbour, the Turner Prize-winning artist Chris Ofili, has described Doig's studio in Trinidad, in one corner of an abandoned rum factory, as

like "an artist's Oxfam, full of paintings hanging around, almost discarded, as

if there are lots of false starts".

Doig takes his time over his work. He listens to music a lot: from Bach to

Rihanna, from soca (Trinidadian music)

to Yellowman, a reggae dancehall superstar. He fixates on one image - a girl on rollerskates, a woman dancing, a man in

a canoe, a wall - and repeats it over and

over again. The paint is layered over time, often over considerable periods of time. Sometimes he feels he is moving closer to pure abstraction, and then he changes tack. "I'm not very disciplined. I don't say: 'I'm going to draw in the morning and paint in the afternoon.' I paint a bit most days, some days more than others. If someone put a camera in my studio, you'd think I was a mental case. Just walking around, not doing much. Sitting down, putting music on …"

But he does eventually finish, even if it takes marathon days and nights of putting oil on canvas, once he is satisfied the painting has been resolved. He mentions a new work particularly, one he "hopes they put up" in Edinburgh. It depicts one of his children in a landscape in the Caribbean. He likes it.

"Sometimes there is just something about a painting - it might be as simple as this sky I painted, which I really like, with these mountains. It actually reminds me, thinking on it, of Scotland. It's actually

a painting of my son, going into this landscape … these mountains …"

He stops and smiles. "Funnily enough, thinking about it, it looks a lot more like Scotland than Trinidad." n

Peter Doig, No Foreign Lands, opens on Saturday, August 3 at the Scottish National Gallery, The Mound, Edinburgh. Tickets £8 (£6). Visit nationalgalleries.org.