There really is nowhere else like it. Tamsin Blanchard visits a shop run by a woman in her nineties, where you can get any style magazine in the world
"There's someone coming to give us training on the new PDs," Dora Franks is telling me. She is bright-eyed and sprightly at ninetysomething, her apricot-rinsed hair shiny and immaculately groomed. She means PCs, but what's in a letter?

Despite her advancing years, Mrs Franks is determined to be on the pulse, if not a few beats before it. Her shop, RD Franks Ltd, Fashion Magazines, Periodical and Technical Booksellers and Workroom Equipment Specialists, is the place to go if you are after the latest copy of cult American quarterly Visionaire (it comes complete with a light box courtesy of Tom Ford at Gucci and features Alexander McQueen's image of an erect penis ejaculating), price pounds 299 and due in stock any day now, this month's Italian Vogue, or a copy of the prose, fashion and fiction periodical, Purple. If they don't have it on the shelves, jam-packed with all the latest quarterlies, monthlies, and weeklies, RD Franks will get it for you.

What Mrs Franks (as she is known by her staff) doesn't know about the world of fashion - be it the colour of the season not just for summer 98 but summer 99 too, or the precise shape of trousers for the season ahead - would not fit on the head of a dress-making pin.

Although she is shocked by the content of some of the cult style magazines as well as most of the men's fashion magazines, Mrs Franks has, after a struggle with her conscience, decided not to censor her stock. Arena might, in her opinion, belong on the top shelf, but she turns a blind eye. "Once somebody asks for a magazine, I have to succumb," she says reluctantly. "No matter what it is, we'll get it for them." And when the internationally famous fashion bookshop goes on the Internet in the next few months, the world will be at Mrs Franks's fingertips.

"You just can't stand still," she says. She does not approve of what is happening in fashion, and eyes my baby-blue suede trainers suspiciously, but she accepts new trends and stocks the relevant magazines accordingly. Her own style was established 30-odd years ago in the days when clothes were made specially for her. She always wears 4-in heels, perfectly manicured bright red nails and precisely-pressed clothes - smart suits and neat shirts - that fit her within a millimetre of her skin. Her hair is always coiffed and she is never seen without a full face of make-up.

While the world of fashion magazines and publishing changes by the minute, the RD Franks shop has managed to remain exactly the same since it became the first tenant of the premises in 1930. It is a bit like stepping into Audrey Hepburn's opening scenes in Funny Face. Mrs Franks inherited the business from her husband, Roy Franks, after he died in the Sixties. Since then, she has personally opened up at 8am and closed at 5pm almost every day. All the greats of fashion design have passed though those original wooden doors at some time in their careers. It is one of the first addresses handed out to the students of Central St Martin's, and many a fashion student - myself included - has blown the equivalent of a week's rent on an irresistible pile of glossy magazines and books at the shop, located in the heart of the rag trade just north of Oxford Street.

RD Franks is one of those family businesses that are a miracle of survival. It is as old as the fashion industry itself. It was opened in 1877 by Roy Franks's grandfather, specialising in selling the finest Parisian lace and jet. The shop's stock has reflected the changes in fashion over the years.

Until after the war, the shop specialised in supplying patterns to customers who would go and have their dresses or suits made at their local tailor. After the war, Franks bought out the competition, Tailor and Cutter and Bells Fashion, and cornered the pattern market. Customers from those days still ring up from time to time in search of a pattern-cutting manual, or simply a chance to reminisce.

However, Mrs Franks has little time for nostalgia. She recalls the golden days of haute couture when she attended the Paris shows and watched aristocratic models - "ladies with titles" - saunter through the showrooms of Balenciaga and Dior. "From those shows, I would see who was covering the fashions and knew which titles to order," she explains. These days, Mrs Franks presides over between 1,500 and 2,000 fashion titles. "We move ahead. We don't look back. In the future, there won't be any books. People will just press a button," she says. Whatever the future holds, RD Franks will be at the cutting edge. "When I'm not here any more, the business will go to my loyal staff," she says in a matter-of-fact way - not before she has prepared the company for the 21st century, however, by installing it on the information superhighway, ensuring that the future of RD Franks is secure for another 120 years.

RD Franks, Market Place, Oxford Circus, London W1 (inquiries, 0171-636 1244)