Success has come at the right time for Scottish singer/songwriter Karine Polwart - but she is no overnight sensation, she tells Tony Clayton-Lea

It's a geography thing - the south-east Scottish border lands provide some of the inspiration behind the songs of BBC Radio 2 Folk Awards winner Karine Polwart. The relative isolation of the region where Polwart lives - beautiful though it certainly is - might offset her lifelong interest in the darker elements of human experience, but she still manages to come up with the kind of utterly compelling contemporary roots/folk songs that make you think deeply about the level of wrongdoing in the material world.

The past 18 months have seen a radical shift in Polwart's career. In 2000, she left her job in a domestic abuse and child protection charity, and started to concentrate full-time on singing and songwriting. Part-time stints in Scottish folk/trad bands Malinky and Battlefield Band only whetted her appetite for a stab at a solo career, and when her debut album, Faultlines, nabbed the Best Album gong at the 2005 BBC Radio 2 awards, it seemed as if south-east Scotland wouldn't be seeing her for quite a while. In short, winning the awards (she scooped two others, and was nominated for five in total) has changed her life.

"Yes, it made a massive difference," she says, "right from when the nominations came out at the tail-end of 2004 until the awards themselves were announced in February of last year. The interest in my music increased at least 10 times from what it was before, and it was all due to simple, obvious things like getting played on the radio and being covered in the press - and people just being curious about the music.

"I sold more records in three weeks than I'd sold in the previous 12 months, so the difference was and is incomparable."

It's even paying off now, she relates, in that media and commercial awareness of her latest album, Scribbled in Chalk, is far stronger than it was for the release of Faultlines in early 2004.

"Interest in Faultlines was good in Scotland, because I have a profile here as a folk singer, but outside Scotland it was a complete struggle," she says. "It was very difficult to get interest in England or Wales, and even more so in Ireland. From record sales to gigs to the numbers of people e-mailing me, to the number of collaborations I've been asked to be involved in - all kinds of stuff have increased since the awards."

Prior to Faultlines, Polwart was operating in something of a vacuum. She had no back-up, was booking her own gigs, and was managing herself.

"I was effectively a one-woman show in terms of my solo work, but that's what most musicians have to do at some point in their careers," she says. "From when I left my job over five years ago, I'd been making a living out of music, but I made Faultlines because I wasn't getting much work in the trad line-ups I'd been in.

"So the solo album was made almost to plug a gap, except it subsequently overtook everything else."

Do some people think she's an overnight sensation, rather than someone who's been plugging away for a while?

"It seems to those who might not have been looking as if I was plucked from obscurity," she says, "and I suppose there is an element of that. For instance, I haven't been grafting as long as other people. I had, however, spent five years plying my trade in bands and sessions, and it's not as if I'd been picked when I wasn't ready for it. I've toured, and gigged, and am capable of talking to people - that's important in the general scheme of things.

"The actual craft of being on a stage, and all the extra stuff that goes along with that, are things I'm quite up for. For me, it happened at the right time. Do I know specifically why it happened to me? No, I don't. I'm conscious that there are many other people out there who are better than me and still relatively unknown. But that's just the way it goes - at the end of the day I'm glad that it's me!"

Irrespective of the "overnight sensation" syndrome, there is no doubt that Polwart is something special. Faultlines is very good and a worthy awards winner, but the new album, Scribbled in Chalk, is even better, a vastly impressive work which has Scottish folk/roots etched on its every crease yet which is also invested with a modernity that few can achieve, let alone get away with.

"My purpose in songwriting is that I want to move people," says Polwart. "I want to say things, make people think, for people to have a response; the songs are not intended to be background music. For me, it's all about words and content.

"That's my job. And that's what folk music is - it's a direct communication between people. If it isn't that, then it becomes a different kind of music altogether."

Industry insiders are talking about a crossover success for Polwart in a KT Tunstall kind of way - how does she feel about that?

"I've heard bits and pieces about that," she answers cautiously. "But my feeling about that kind of talk is that I'll just go with the flow. I wouldn't want to anticipate anything. I mean, two years ago I could never have anticipated any of the things that have happened to me over the past 18 months, so I think it's better not to second-guess things. It's not being optimistic or pessimistic; it's being neither. Rather, it's about doing your gig and enjoying it, and not doing things to please people."

Polwart realises that what has happened to her recently - her songs being played on the radio, international media coverage - doesn't guarantee anything at all, but she knows it gives her a better chance of at least consolidating her success, if not bettering it.

"Ultimately, people will like or dislike my music," she says. "I'm ever so slightly wary of people expecting too much, because I know full well there are many good ways of making a living without being in any way publicly recognised. If the truth be told, I'll be satisfied with whatever happens."

• Karine Polwart's album, Scribbled in Chalk, is on release from Spit & Polish. She plays Whelan's, Dublin, on Mon, Jun 26