Dream team

“Oh, there are things we disagree on,” says Thornton. “Colour! We can talk about shades of nude for three hours.”

“I suppose it’s not so much that we disagree, more that we debate,” adds Bregazzi diplomatically. “But I suppose we debate in a coupley way rather than a professional way.”

Thornton and Bregazzi have been a couple since they were teenagers. They have been designing together for 19 years, showing at London Fashion Week for more than a decade, and will unveil their spring/summer 2012 collection at LFW this Friday.

They both grew up on the Isle of Man, where they first met aged 18, establishing their business soon after. Today we meet in their airy London studio, where rails of bright clothes stand out against whitewashed walls and staff busy themselves with the Spring/Summer 2012 collection while a mischievous mutt pads around at their feet.

In contrast to the rows of colourful clothes, the couple wear sombre shades of grey and black. Indeed, the only nod to colour between them is Bregazzi’s shock of red curls. But then Preen is a label of contrasts, at once sexy and subdued, high-fashion and utterly classic.

Think of Preen and you might think of Michelle Obama in a minimal blue skirt suit. Or perhaps Amy Winehouse in an acid yellow power bandage dress over a black push-up bra. Then there’s Beyoncé in soft florals, Paris Hilton in a barely there white mini-dress, Cheryl Cole in leather and Gwyneth Paltrow in a Little Black Dress.

Preen is many things to many people, the result, perhaps, of a label honed and refined by a design duo unafraid of change. The London-based label started out as a small Portobello Road boutique from which Thornton and Bregazzi recycled vintage pieces. It became a magnet for stylists and celebrities, and the couple’s fashion star grew from there.

Today the label – which has two lines, Preen Collection and Preen Line – is carried by 120 stockists in 25 countries, and, while retaining an identifiably Preen thread running from collection to collection, Thornton and Bregazzi love to experiment rather than be bound to a structured “look”. “Sometimes when it comes out on the catwalk,” says Bregazzi, “I’ll think ‘God, this is so different from anything we’ve done before’. But people will still say that you can see the Preen signature.”

In the absence of something more tangible, one might say that that “signature” is simply that Preen make clothes that flatter women. It sounds obvious, but in the world of high- fashion, the concept of clothes that make the wearer look good is by no means a given. Such thinking seems to be perceived as an acknowledgement both that clients don’t all have model figures, and that fashion to many can serve a very practical purpose rather than existing on some higher plane.

“We are quite intuitive so we are quite free with what we design,” says Bregazzi. “The thing we always think about is how to flatter women and what women want at this moment in time. I know the problem areas that women usually want to cover up, their arms perhaps, or their hips. We have a lot of customers with fantastic figures but we do try to think of as many different shapes as we can.”

Preen manages to strike the tricky balance between clothes that women want to wear and clothes that men want to look at. Is this a result of having both a man and a woman at the helm?

“I think that works really well for us,” says Thornton. “Because what I might think looks great on a woman, Thea will say, ‘yes Justin, but she needs to be able to wear underwear with it’.” They both burst out laughing as he mimics tugging down at a too-short hemline.

Did such a compromise exist before Preen? Possibly not. We can pinpoint the exact moment Preen brought sexy back. It was 2006 and the duo were looking to the original supermodels for inspiration. Bregazzi wondered out loud if it would be possible to create something that made everyone look like a supermodel, and so the Power Dress was born.

“We wanted a dress that shrank your waist and puffed out a little bit at the hips,” explains Thornton. “Something that would work on a flat chest or a large bust. These skinny body-con dresses that were around, they showed your belly button, they showed everything. You couldn’t wear underwear with them.”

The dress was an immediate hit. It hugged in all the right places, skimming over “problem” areas and showing just the right amount of flesh. It was immediately adopted by celebrities whose wardrobes might not necessarily have overlapped before; Agyness Deyn, Gwyneth Paltrow, Amy Winehouse, Girls Aloud. Once Kate Moss wore it, it had officially landed, and it has appeared in some shape or form in every one of their collections since.

Indeed, when searching for inspiration, the designers are as likely to look to their own extensive archive as they are to travel, music, film or literature. “It’s interesting the way we’ve developed and the way that we design now,” says Thornton.

“When we started we would cut up vintage pieces and create new shapes, where now we end up cutting up our own designs from the archive. The bottom of a skirt and the top of a dress might be put together for a new season. It helps you retain your signature and build your brand, because it’s important to have pieces people recognise travelling through your collections.”

The appeal of their most famous piece to date was simple: sex. “At the end of the day, every woman, even if it’s in an understated way in a man’s suit, perhaps, she wants to feel a bit sexy,” says Bregazzi. “We had never before really done an obviously sexy dress and we wanted to do it in a way that our friends could wear it. ”

It’s interesting just how willing to learn the couple are, even after two decades in fashion. They listen to their friends – mothers, businesswomen, fashion industry insiders – and ask them what they want to wear. When something feels right they go with it, even if it’s a path they haven’t explored previously. They’re very aware at the moment, for example, that the concept of dressing for one’s age is becoming an increasingly vague one.

“We’ve always wanted to discover what’s new, because women are always changing,” says Bregazzi. “Five years ago when designing a collection you’d know what was for a young girl and what was for an older girl. Now ages are blurring. Forty isn’t old at all any more.”

“It’s interesting the way that fashion rolls and changes,” adds Thornton. “We kind of push ourselves to try and look at things that you wouldn’t think to look at – how to make a two-piece skirt suit cool, perhaps. Or with this resort collection we went all out on print and colour and we don’t normally do that. I think it’s so bright because we like to challenge ourselves. That’s what keeps it new and exciting. For years grey was our favourite colour, but if you don’t keep moving then you just become stagnant.”

There is another possible explanation for their newfound love of colour. The couple have a three-year-old daughter, Fauve, and are entertaining the possibility that all the bright toys which have overtaken their London home may have something to do with it.

Beyond acting as a source of inspiration, however, Fauve’s arrival has had minimal impact on their working lives. After just a month of maternity leave, Bregazzi brought her to the studio every day. It was only when she interrupted a meeting in Selfridge’s by blowing raspberries that they decided to employ a nanny part-time.

“She has enriched our lives completely,” says Bregazzi, who spends three days a week in the studio. “Plus it makes you look at things from a child’s perspective, which is lovely. But we’re running on no sleep, of course. And it’s definitely not through going out partying.”

The couple are together “24/7” but insist that they don’t come up against problems living, working and raising a child together. Their desks are opposite each other in the spacious studio and they work together on “absolutely everything, always at the same time”.

They finish each other’s sentences, and each nods quietly as the other speaks. They bring different things to the business, but share the same tastes. They agree on almost everything, but rather enjoy the occasional dispute. “Generally we will walk into a room, a shop, a space and we will always both like the same piece,” says Thornton.

“I suppose what it comes down to,” adds Bregazzi, “is that we’ve just both always wanted to create nice clothes that people wanted to wear.” Her partner nods his assent.

Preen will show their SS12 collection at London Fashion Week on Friday. Visit www.preen.eu for details.