Paul Smith's signature logo has become globally recognised. Katharine Hamnett has won international notoriety for her environmental campaigning. The names of Nicole Farhi and John Rocha are well known. And yet one British-based designer, and their contemporary, remains more of a niche affair - despite a CBE for services to fashion and a following verging on the cultish, since she started out 40 years ago this year. Perhaps the rather English reserve of both designer and designs alike are to blame.
"Successful fashion designers tend to think in terms of themes. But for me it's just about the individual piece," explains Margaret Howell. "I've always liked that philosophy of homing in on details and sticking with something when you like it and I appreciate that sense of feeling self-conscious in anything too 'designed', the kind of thing that can make you feel like you're wearing a costume. I'd have been a disaster at fashion college because what I'd want to get across wouldn't work in a sketch. It wouldn't be exciting enough."
That lack of excitement has paid off, however, leaving her somewhat under the radar but sufficiently above it to build a US$97m (Dh356m) business employing 500 people - with the company's first store outside of the UK, which opened in Paris in 2009, now set to be followed by a spate of shop openings around the globe, with the Middle East in line for a store, plugging the gap between the UK and the Far East. The latter is so drawn to her fastidiousness of manufacture and ease of wear - layering up or down to suit all climates is a Howell trademark - that it alone accounts for 80 per cent of sales.
It has also given the brand a ferociously loyal clientele; one sufficiently engaged, in fact, that some write to her to complain when they think the models in her ad campaigns are - how shocking - too young for their liking. "The thing is," says Howell, "some of our customers have been with us since the 1970s and, well, they are older now. I like to write back to them, though."
It is a loyalty likely to be extended through this international expansion - proof, of a kind, that rigorous design rather than flighty seasonal extremes has its adherents.
"A fashion designer? No, I've never thought of myself as that," Howell says, as though fashion was highly suspect. "A designer of clothes, but not fashion. My choice in clothes has always been quite conservative. Besides, the real fashion thing is actually a very small group of people. Out on the street you don't see many people you'd call fashionable, do you? There aren't many people wearing Vivienne Westwood."
Indeed, Howell places her clothing within the broader context of design. She has a parallel life as a champion of British design, from Ercol to Ernest Race, via Angelpoise lamps and Robert Welch cutlery, reviving forgotten classics through special editions in a way that, should there ever be a 21st-century festival of Britain, would make her an ideal curator - and not least because, whenever possible, she has had her goods made in the UK too, typically working with specialists in their field. Fine knitwear, for example, is made by John Smedley, one of the world's oldest continually operational manufacturers, while macs are made by the garment's inventor, Mackintosh.
"All those English fabrics, they were pretty good when I started out," Howell adds, with something of a lament. "But I suppose their decline was predictable. They kept using these ancient but extremely robust machines because they just kept going, while companies abroad were investing in technology, and, of course, in design. But I still feel a responsibility to make in England and back English products because a lot of it is still just so good."
That, inevitably, also tends to make it rather expensive. Add in Howell's artsy, slightly Bohemian aesthetic and it is small wonder that she is outfitter to the middle-class creative echelons - writers and craftspeople, actors and industrial designers, such as Sam Hecht or Kenneth Grange, with both of whom she has recently collaborated on limited-edition shirts. It would be in keeping with Howell's beginnings: she was the fine arts graduate of London's Goldsmith's College who discovered a man's shirt in a jumble sale, was inspired to establish a design studio to make her own, found a fan base, sold to Ralph Lauren and, seven years later, opened her first shop backed by the fashion entrepreneur Joseph Ettedgui. "And I'd quite like it if people did think of what I do as 'artsy' because fine art is my background," says Howell, "and the clothes do tend to appeal to people in the arts worlds, perhaps to people who don't want to feel smartly dressed but need the quality."
The womenswear for spring/summer, for example, includes simple white shift dresses, straight-legged navy trousers, Breton tops, knee-length schoolgirlish skirts and plain patch-pocket blouses - none of it offering the high glamour of most catwalk designers, but all of it with a utilitarian edge that will guarantee it will still be worn years from now.
The menswear, meanwhile, is all shades of charcoal, khaki and washed-out blues, granddad-collar shirts, unstructured tailoring and washed-out cotton drill trousers. Both women's and menswear reflect the design-for-purposefulness of workwear - born, Howell suggests, of messy art college days in which its indestructibility and readiness to withstand regular laundering first won her appreciation - without tripping over into either, respectively, the mannish or the cartoonish.
"I like the iconic things on which menswear is based and I don't like anything that's extreme for the sake of it, which is especially important in menswear," Howell explains. "Menswear is all about references and everything I design has to be designed with a reference point in mind. That gives the garment character - otherwise a raincoat is just a raincoat. It is a largely subconscious approach to design, but I know when an item just feels right. You can get the same feeling from old clothes. Even if I don't wear something any more I find it hard to throw it out if I remember how nice it used to be to wear it. An old cashmere sweater, even one full of holes, still makes you feel right."
Indeed, some have described Howell's collections as embodying off-the-shelf the attractive familiarity one finds in clothes that have stood the test of time and still remain wardrobe favourites. Loving the time-worn and textural is, she suggests, a rather English attitude - and that is perhaps the characteristic that best distinguishes Howell from her better-known peers. Small wonder she was requested to design the uniforms for the staff of that quintessentially British institution, the Victoria & Albert Museum.
"That sense of Englishness is an inheritance," says the designer. "I remember the feel of this piece of linen a great aunt gave me as a child, or my granddad's old oak chests, or the grain on the groynes worn down by the sea by my house," she says. "Some designers are only forward-looking, and want to use the latest technologies. But I'm probably a product of growing up in England after the war. I was brought up with that austerity attitude - with a love of tradition, to respect things, not to have lots but one good one."