KEY POINTS:
First of all, we always start with colour," says Betty Jackson, dressed head-to-toe in black, with characteristically patrician hauteur. Lest any upstart journalist even think about sticking an oar in, she continues: "I love dark colours in the sunshine. I think they work brilliantly."
They most certainly do
in this instance. In fact, with her trademark silver hair and slash of red lipstick, no one could be a better advertisement for dressing in sombre hues, whatever the weather, than Jackson.
At 57, the designer - who was honoured with a CBE last month - is as elegant now as she ever was, and could teach most women a thing or two about style. Not that she'd admit as much.
"I don't have it," she says dismissively before moving on. Anyone who has ever met her would doubtless beg to differ. Perhaps any reticence to blow her own trumpet is attributable to her country of birth.
"The British will always be embarrassed about style," she says. "They don't teach it, they don't celebrate it, they don't revere it." Betty Jackson is not a woman famed for mincing her words.
A northerner born and bred, there's nothing even remotely pretentious about her. Instead, for more than 25 years, she has worked away quietly and consistently, rising above the hype generated by her younger counterparts.
Jackson makes comfortable clothes in luxurious fabrics that refuse to age or date and that pay lip-service to fashion's prevailing mood without being enslaved by it. "I hate being uncomfortable. It's so unnecessary."
Today, Jackson is something of a grande dame in British fashion circles: she is a much-loved fixture of the twice-yearly London collections and remains entirely in control of her own company which is, in itself, quite remarkable.
"I think people always want to put British fashion into a box of being only about innovative stuff, but I lament that London is always looking for the next bright young thing who, in the end, probably won't be able to sustain it."
Jackson should know. In the early 80s her clothes were just as much in demand as, say, Christopher Kane's or Giles Deacon's are today.
"It was such an exciting time. It must have been around 1983.
"We were overrun with Americans screaming for the stuff because nobody else had the sort of independent image we had.
"They were just dropping money. You wouldn't believe it. We had queues outside. It was a meteoric rise and a bit scary because we really didn't know what we were doing.
"We were working from tiny premises and trying desperately to get things made without understanding the international level we were playing on. We were silly about delivery dates, about quality. And then, overnight, it all just stopped."
Jackson was born in Bacup, Lancashire, in 1949. Her father owned a shoe factory and was none too pleased when his daughter announced her plan to go to art school.
"You really weren't supposed to do that sort of thing. I expected to be whizzed off to London and have an exciting time - you know, all sex and drugs and rock'n'roll but he had the last laugh and sent me to do a foundation course at Rochdale Art College, about eight miles down the road. Not entirely glamorous."
Glamorous or not, Jackson had found her milieu. She went on to study fashion in Birmingham.
"It wasn't a blinding flash or anything. I got into fashion by a process of elimination. I love the feel of fabric and it just evolved from there."
In 1971, she had a serious car crash in which she badly damaged her leg. It took two years to recover.
"I think it taught me about being able to overcome anything. It made me very strong-willed, although other people would probably say I was very bossy beforehand, too."
After completing her degree, Jackson became an illustrator for the company that went on to become Fenn Wright Manson.
In the late-70s she worked as a designer for Quorum, presided over by Ossie Clarke, by that time well past his prime, but a fashion superstar nonetheless.
"He was unharnessably brilliant. I was absolutely terrified of him."
Aged 30, on holiday in Majorca, she met her French-born husband, David Cohen, who persuaded her to go into business in her own right.
Today, he is her business partner. They live in west London and have two children, Pascale, 22, and Oliver, 20.
By 1981, the initial wave of hype surrounding Jackson had reached fever-pitch. "Then Britain was hit by recession and it all just ground to a halt."
Jackson was forced to restructure her company and rebuild her customer base entirely.
More than a quarter of a century on, Jackson's business is still small by international fashion standards.
Her turnover for the past financial year was £4 million ($10.4 million). She is stocked in independent boutiques the world over, and has a flagship store in London's South Kensington.
Her business is supported, at least in part, by her range for Debenhams, Betty Jackson Black, which she has designed since 2005.
"We are self-financed and whatever we make one season we plough into the next. There's never any left over. We made the decision a long time ago to keep the business small.
"The consequences are that we can't afford an advertising campaign which would give us more visibility. On the plus side, we have kept relatively sane."
Jackson has also kept many very loyal customers happy over the years.
"We have an amazing following. People travel to London just for us.
"The advantage, of course, is that if you are going to wear me to something, you are not likely to see three of me there. I think people are really beginning to appreciate that."
They also appreciate clothing that is as beautifully made as it is a pleasure to wear.
"You've got to be able to shove something on and forget about it. Clothes should do a job for you. They should be a tool to be used how you wish to use them.
"Practicalities aside, however, I also think it's a bit like falling in love."