Interview: Fashion designer Jonathan Saunders

The temperature outside is tickling the mid-twenties and sunlight streams in from above, bouncing off brilliant white walls and making me squint. Neatly arranged on every available wall are drawings, photographs and neon post-it notes, creating an enormous mood board that fills the room with colour. Amidst it all, the 29-year-old Scottish fashion designer is dressed, head-to-toe, in black.

For a designer renowned for his use of colour, it seems to be an unusual choice. He laughs – letting out a cloud of smoke – when I ask if this is the norm.

"Usually over the show time, yes it is. Because I get so saturated in colour. Whatever I'm feeling, it's always colour research that I start with. It's the first thing I start to look at for a collection. Maybe it's a Glasgow thing as well. Like flamboyance, it's not so good for a man, is it?"

Certainly, Saunders is as far from the flamboyant, Bruno-esque fashion-designer stereotype as it's possible to be. Today he sports a black v-neck T-shirt with a thin, silver chain and black jeans. He wears his hair in a close-cropped buzz cut, his stubble the same length. He is extremely handsome, with olive skin and brooding, youthful features, and if not for the tinges of grey at his temples he might look like any jobless art student in his twenties.

His Staffordshire terrier, Amber, perches on his knee as he chain smokes. Visually, Saunders might cut rather an intimidating figure. His chuckle, punctuating his sentences, cuts straight through this image however. It's long, low, mischievous and unmistakably Glaswegian (the accent hasn't faded a bit).

Today he's surprisingly relaxed considering that his spring/summer 2010 show on 22 September is creeping ever closer and his entire collection remains at the toiles and tacking stage ("everything's so hideously late as per usual because the Italians shut down for August – nightmare" he says with a resigned wave of his hand). But then, this show will mark the Glasgow-born designer's homecoming, and he's feeling, he says, more positive than he has in a while.

Since graduating from Glasgow School of Art in 1999 with a BA in printed textiles, his career has followed something of a fairy-tale arc. After graduating, he gained a place on the famous MA course at London's Central Saint Martins, juggling three jobs while working his way through one of the most intensive courses in the business. He was snapped up by Alexander McQueen within 48 hours of his now-legendary graduate show, and within a year made his catwalk debut at London Fashion Week, aged just 25, with the international fashion press hailing him as a "show-stealing wunderkind".

He now shows four collections a year for his own label and two for Milan-based label Pollini, and celebrity fans include Kylie Minogue, Madonna, Sienna Miller, Michelle Obama and Thandie Newton. In February 2008, he took his collection to New York Fashion Week, undoubtedly a brighter showcase than the more edgy, but less commercially influential, London equivalent.

This season, however, he's been tempted back to the fashion week that made his name – alongside Brit designers Burberry, Pringle of Scotland and Matthew Williamson – and he's happy to be home.

"Coming to London (from Scotland] was an extreme change in that self-promotion is key," he says. "But then New York, that is another level. I can't imagine anything more different from a Scottish attitude to life than a New Yorker's attitude to life, just because it's so much about self-promotion. It goes against the grain for me. Everything is work, everything is about promoting yourself, voicing your opinion. Your tongue is exhausted when you leave. And I think, 'if my friends back in Scotland could hear me now!' So London feels a little bit closer to home. When you take something on a road trip, to come back, it's much more personal."

If self-promotion isn't Saunders's thing – certainly, he doesn't work it yet with the flair of a New Yorker – perhaps he's lucky that his work speaks for itself. He flicks proudly through a rail of designs for his current Cruise collection, but it's his PR who is really gushing over the muted neon. Who can blame her? Saunders has won praise throughout the fashion world for his bold, silk-screen pieces which forgo repeat patterns in favour of large-scale prints that work with the cut of the cloth. Using traditional techniques, with as many as 20 screens per design, the result is a harmonious fusion of print and form: the print is the garment and the garment is the print.

"I've always loved abstract imagery and that lends itself very well to textiles, but I also wanted to see how relevant that was to fashion," he says. "Previously, I found that textiles within fashion were almost secondary. Maybe it was my ego, but I wanted to make them the most important thing. So that's where this engineering print around the garment idea (came from]. It's the colour, it's how it lightens you, changes the mood. That's what print can do, that's what colour can do. I think there is pressure if you are known for a specific thing – for example as a textiles designer – because of the nature of the industry the first thing people will say is that it's all you can do. So you start on this crusade of trying to prove that that isn't all you can do. But why not just do that?"

Saunders was artistic as a child, but unlike many designers didn't harbour any fantasies about high fashion until he was at college ("I didn't grow up as a kid dreaming of frocks by any means, not at all"). The son of Jehovah's Witness ministers, he is cagey about his upbringing and won't be drawn on his relationship with his parents, saying only, with a firm but friendly smile: "I've always made my own decisions and done what I wanted to do and I'm sure they're fine about it."

He is reluctant too, to talk about his more rebellious teen years. He was something of a late bloomer at college, studying product design before switching to textiles, and the temptations of student life at Glasgow School of Art proved hard to resist. He doesn't want to dwell on this period, offering up just one funny anecdote while giggling uncontrollably.

"All of the girls on my course were so lovely – you know weavers are a certain type of girl? We all went to Premiere Vision (a biennial French textiles trade show) and I took the girls out to show them Paris. They never got home, they missed the train to go to Premiere Vision which was the whole point of the trip and it was all my fault. We turned up for the train and we had cartons of red wine in our hands. We missed our stop and ended up completely lost somewhere in the south of France."

With this exception, Saunders tends to keep pretty schtum on his personal life, but concedes that he's more happy, relaxed and balanced than ever before, and this upbeat mood has clearly influenced his spring/summer 2010 collection. He is vague when describing it, but not, I get the impression, because he is holding anything back. Despite his experiences in New York, he doesn't seem particularly good at expressing his creativity verbally. He gestures at sketches and photographs as he talks, prodding occasionally at a colour he finds particularly inspiring, a dusky coral or a greying turquoise.

"The new collection feels very personal to me," he says, lighting another cigarette, "so colour and print will feature, but also there was a naivety when I first started because I didn't have training in terms of pattern cutting and structure of garments. I worked with shapes that were much softer, much easier by default. And I feel that's kind of relevant now, a sense of ease, lightness. (The current collection] as proud of it as I am, everything is always a reaction against what you've worked on and I was probably the most exhausted I've ever been when I did the last show so there's a sense of darkness there. The colour, the red and black ... the way you feel is always reflected in what you make. And there was a real fighting spirit last season, a sense of uncertainty, so there was a need for this strong, powerful woman in my eyes. Now I just feel much happier and I need something light."

Certainly he seems happy. Interview a designer just days before their show and too often you find a bedraggled husk of a person, hunched over a sewing machine, a half-eaten can of baked beans – with a sticky fork poking out of the top – beside them. Tanned and beaming, Saunders seems as far removed from the image of the stressed-creative-on-the-verge-of-a-breakdown as possible.

"I think I'm just a bit of a fighter," he says. "That's the Scottish thing as well. I used to wallow in it. I loved the martyrdom. How many late nights could I have slaving over a print table producing these elaborate textiles while eating beans? I wallowed in it and I loved it. That's really Scottish. It's now a standing joke that we're not allowed to be martyrs any more, we're not allowed to do that."

Is he still allowed to eat cold baked beans straight from the can though? "Oh yes!" he laughs, enthusiastically. "Always."

Jonathan Saunders's spring/summer 2010 collection shows at London Fashion Week, 22 September, www.jonathan-saunders.com