Fashion: Yves, Sonia et Christian say merci: Once a year the couturiers of Paris come down from their thrones to celebrate their wondrous seamstresses. Marion Hume was there with her plume, and Herbie Knott with his lens

ONCE a year, tipsy young seamstresses, flushed rosy-pink with free champagne, walk the streets of Paris looking for husbands. Each girl wears a jaunty green and yellow bonnet, a gift from her couturier boss, to signal that she is ready to be taken out of apprenticeship and ripe to be wed.

The 25th of November is St Catherine's day and at least some of its traditions live on. It is the festival of the 'Catherinettes', for all unmarried girls in their 25th year who are employed in fashion. 'Once, we were supposed to be virgins as well. Now they don't dare ask us]' giggles Valerie Servant, of Sonia Rykiel.

St Catherine, like all good Catholic saints, was presumably a virgin when she met with her beatific sticky end on a wheel. But no one at the St Catherine's day party at the Hotel de Ville appears to know who she was or what she did to qualify for the task of watching over these unmarried women. 'I know she is the patron of our little workers, and for one day they need do no work, but I don't know why,' says Jacques Mouclier, the arch-traditionalist president of the French federation of haute couture.

No matter, it is an excuse for a party, a chance to out-do other couture houses with the magnificence of one's bonnet and an opportunity for some old-fashioned coquetry. 'Bravo mes Catherinettes] Come over here]' shouts the waiter loitering in the doorway of a corner bar waiting the lunchtime crowd. Women who would habitually tell him where to get off give him the doe- eyed come-ons from beneath the brims of exaggerated hats.

These are always green and yellow; green to signify hope that a husband will soon be found and yellow in reference to the trousseau of linen that the mother of the girl would have started when she was 17, now yellowing in the bottom drawer. The couturiers also give each girl presents for the home she'll set up with her husband. Christian Lacroix presented each of his five Catherinettes with bound albums for future wedding photographs, and a table lamp.

Lacroix also gave each girl a couture suit, in daffodil yellow or apple green, to wear for the day and keep for life. 'Of course I'll keep it. My mother was a Catherinette in the atelier of Hermes, and my grandmother can remember the girls parading the street in her day,' says Charlotte Lebhard, from Lacroix.

The outrageous confections on the catwalks of haute couture are often little more than advertising tools in order to sell perfume and cosmetics. But St Catherine's day is, officially, not just another photo-opportunity to sell fragrance off the back of some free publicity. The parties held on the eve of St Catherine's day in the top couture houses are strictly private.

So we were unable to witness the traditional dance of each Catherinette with her boss. However, the girls from Lacroix confirmed that the couturier, who relishes the traditions of his metier, did indeed take each of them for a spin. Allegedly, even Yves Saint Laurent dances with his Catherinettes, which is surprising considering the difficulty he has walking down the catwalk at the end of his shows. He also makes a point of designing individual hats and 'chapotting' - putting the hat on - each Catherinette himself.

Other designers do not. When the two Catherinettes from Balmain were asked if their new boss, Oscar de la Renta, had designed their bonnets and danced with them, they replied that of course he hadn't, 'because he's an American'. Gianfranco Ferre, of Dior, who is Italian, made each of his charges a hat with distinctive gold CD letters on the brim, but seemingly declined to dance. Karl Lagerfeld, who is German, wasn't even there. He left the feast of the Catherinettes chez Chanel to Gilles Dufour, his French design chief.

Traditionally, the day starts with Mass for St Catherine at St Pierre de Chaillot. This year, most Catherinettes opted for a lie-in instead and reserved their bonnets for secular attention, 'anyway, we had to be in the office to have our make-up done at 8am', said the girls from Chanel. Conveniently, there were seven girls in their 25th year at Chanel, which was just the right number for each hat to bear a letter of the brand name. Coco's Catherinettes made a late entrance, just to ensure that, as usual, Chanel stole the show.

But the friendly competition was stiff. Originally, the Catherinettes wore simple lace bonnets with yellow and green ribbons, but perhaps with the needs of the modern-day single woman on a man-search in mind, today's efforts are far more attention grabbing. Sabine Bloch, of Angelo Tarlazzi, was sporting a hat-sized version of one of those plastic bubble gee-gaws you shake upside down to see snow; one Taiwanese student enrolled at the Chambre Syndicale de la Haute Couture had pierced the brim of her green straw cartwheel with yellow scissors which perched on her nose as spectacles; while Isabelle Ceccon, a seamstress who specialises in G-strings for the dancers at the Lido, appeared with a Busby Berkeley Sweeping Staircase complete with a topless Barbie doll on

her head, and then explained precisely why

haute couture skills are needed to construct the slivers of nothingness barely worn by the Lido dancers.

Hats of yellow and green camellias with fake blonde plaits attached turned out to belong to a pack of girls from Chanel's cosmetic and perfume businesses - who are not truly eligible to be Catherinettes but, as with the virginity issue, no body seemed to mind. 'We even allow young women from pret-a-porter now,' explained Jacques Mouclier.

The only young women not in green and yellow had opted for sophisticated straw hats in beige. 'We wanted to distinguish ourselves from the seamstresses. We are from L'Institut Francais de la Mode,' explained one high-flying business student from Paris's tough fashion management college, which was founded by Saint Laurent's money man and president, Pierre Berge. 'We are not traditionalists at all.' Why then were she and her classmates here? 'Well, we are not married . . .'

She was, however, too modern to make the traditional pilgrimage to the statue of St Catherine in Le Sentier, the rag-trade district of Paris that was once packed to the rafters with seamstresses. There, Catherinettes traditionally offer yellow and green floral tributes in the hope of gettting their man. Nine single Sonia Rykiel Catherinettes made the journey, all wearing identical hats and vivid feather boas that were theirs to keep and diamante-encrusted dark glasses that had to be returned to stock.

They had some trouble locating their patron saint. At last someone spotted all three stone of her, balancing ignobly on a plinth above a branch of the Union Bank of Paris and only visible from the street if someone told you where to look. But passers-by knew all about why the girls in their bright bonnets were charming the bank manager to let them up the first floor windows next to the statue to pay tribute. 'And come over here afterwards]' hollered workmen in the cafe opposite.

To others, the Catherinettes tugged at the heartstrings. There has traditionally been tremendous popularity for working-girl heroines in French folklore and here they were in the modern world. Women came out of the fabric showrooms and button-makers' workrooms to cheer. One elderly lady was in tears: 'Ah, mes Catherinettes, you are so few,' she whispered. 'In my day, we were many. And what a fete we had, ooh la la]'

'We spend our lives being capable working women in a big city, and for one day we are marriage bait,' laughs Valerie Servant, 'but, you know, it is fun for the day.'

(Photographs omitted)