In the auction houses, a lot of value of course comes from the provenance of pieces. Diana's black knee-length dress by Christina Stambolian fetched pounds 65,000 at Christie's New York auction of the Princess's dresses in 1997. Christina Stambolian? Who? Diana eclipsing her husband's television adultery confession by arriving ravishingly decolletee at a Serpentine Gallery reception? Now that does ring bells. "Buying these dresses is like buying a bit of the Berlin Wall, only they're a damn sight prettier than a clump of Stalinist rock," said a German buyer at the time.
A few months later, the property of Janet Street Porter limped its way out of a Christie's South Kensington Fashion and Textile sale. Despite many pieces having been specially made, and others having lots of fashion history credibility, a deep resistance to the cast offs of an 1980s media ego pervaded the sale room. A perfectly formed Vivienne Westwood Buffalo Girl suit - put firmly in its place by catalogue speak: "in brown and black herringbone effect wool, all labelled MCLAREN WESTWOOD WORLD'S END" - from the autumn winter 1982/3 only managed to slide beyond its estimated pounds 200 to pounds 400 by pounds 2.
"It did feel like people had a problem with her," says Judith Clark, who, as a fashion collector not averse to making the odd saleroom purchase herself, was also at Christie's. Clark's reasons for buying into fashion and costume, however, are rather different from your average auction goer. They are generally "struck by aesthetics," according to Kerry Taylor, head of costume and textiles at Sotheby's London. "It's the rarity, beauty and condition of pieces that matter first and foremost." Clark's concerns run a little deeper.
She hasn't just been collecting clothing for a while, but also studying it, albeit somewhat against the odds. As a student of architecture, she ended up at the Architectural Association in London - an institution not known for its traditionalism or conventionalism - but found that even there resistance to taking costume and fashion seriously as three-dimensional design and a subject for anthropological study was enormous. If she wasn't prepared to talk about buildings, no one was prepared to listen. She started a PhD, but gave up in despair.
Instead, in a corner of Notting Hill that has already about as much fashionableness as a street could ever need (supermodel addresses; Kate Moss and Johnny Depp giggling over their caffe macchiati in Coins cafe) Clark has channelled her passion into opening her own place: London's first private gallery of fashion. Far from being a smart way to sell currently hip second-hand couture to the locals, Clark's mission is to explore how the meaning of clothes can be explained and re-evaluated in a white wall space. As well, of course, as showcasing very beautiful pieces of design. "These things are worth looking at," she says. "Take some of the pieces at the latest couture shows. Those Dior outfits [by John Galliano] cost up to pounds 30,000 to produce. They are incredible. Why should they be seen once only?"
Clark's preoccupation isn't just with the contemporary. Among her own prized possessions is an original costume by Leon Bakst (the stage designer of Diaghlev's Ballet Russe in the 1910s and 20s), bought in the 1995 Castle Howard sale. A perfect example of how things are (and aren't) valued in a society that places the fine arts in prime place and design way down the line, the entire dancer's outfit (top, trousers, hat, accessories) cost pounds 5,000 - "nothing," she avers, "compared to the price that Bakst's drawings would fetch." A belle epoque show is being researched and Baroness Thyssen, a face of the 1950s, has promised to loan some of her collection of that decade's couture in support of Clark's project. (Clark, a 30-or- so-year-old Australian who grew up in Rome, is nothing if not well-connected, it seems. And presumably rather well-to-do.)
The gallery opened yesterday with a show of 12 new pieces by designer/maker Dai Rees that has already enabled its owner to prove one point: that the wearable can also be worth contemplation. It is hard to know what to call Rees's offerings - hats? head-dresses? - that blur the boundaries between headwear and jewellery. But at their best they are pure sculpture and it is the beauty and complexity of their construction and craft that is given a serious airing in the cool white space.
Made principally from bird quills and feathers - often flocked, sometimes spiked with sharp silver points, glittering with hundreds of diamante pieces, dyed, or feathered but always reinvented in some way - Rees's work draws from the natural world to create the strange and synthetic. A sheep's pelvis, found on a beach, is at the heart of one head-dress - encrusted with white diamante it has become sparkling jewellery. Like the plumage from which they are often created, they are attractive and repellent in equal measure. Their price tags (pounds 2,000 plus) reflect the work, skill and consideration that goes into each design.
On the catwalk (Alexander McQueen used Rees's work in his spring/summer 1997 show), it is the aggressive and unsettling nature of the headwear that comes into play. When worn, they are more likely to provoke a discussion about ideas of beauty, or at least to unsettle. Recently Clark wore a leather and quill piece that wraps around the face - one that had been seen at the McQueen show - to a private view and received offended reactions from other women there. "They seemed angry. They said things like, 'do you have to wear that?'," reported Rees later.
Clark is not the only person brave enough to have both invested in and worn Rees's work. Annabel Rothschild bought the three most extreme examples from the McQueen collection and has done exactly what Clark hopes will happen to most objects that are sold from her gallery. "I hope that things will be worn, and then displayed in people's homes. It's not like these things must be treated like art, must be revered. Surely they can be enjoyed in a more practical way, too." Which, of course, makes them sound like a better investment all the time.
Judith Clark, 112 Talbot Road, W11, 0171 727 2754