Lycra, the elastomeric yarn which brought sensuality to gym and track, fame to Azzedine Alaa, Liza Bruce, Flo-Jo and Madonna, and fresh fortunes to Donna Karan, Marks & Spencer and Danskin, appears to have been marooned by the retreating tide of fashion.
Only a year ago a bright young woman responsible for womenswear at BHS contradicted me: 'Leggings finished? Oh no, the 60-year-olds are just getting into them. It took them a while to discover how comfortable they are and now there'll be no stopping them.'
Without Lycra the principal boy look of leggings would have been impossible. Without Lycra, wool or cotton jersey would bag, sag and wrinkle in unflattering folds.
Nor would the micro-skirt have been even halfway decent. Without the give of Lycra, the skirt would have needed a stride-accommodating slit - which would have rendered petty considerations about a visible panty line utterly redundant.
But fashion is once again all about volumes of fabric, about fluidity and floatiness, soft silhouettes and softer fabrics. Does Lycra have a place in all this? In Geneva, Anette Bogstad, European PR co-ordinator for Lycra, concedes that sales of the yarn to outerwear manufacturers have declined.
'But,' she says, 'the decline has been compensated for by sales in many other areas, chiefly hosiery. Clothes are not going to be tight next summer but we are certainly going to be showing a lot of leg. Hosiery manufacturers have already invested a lot of money in tights.'
Not a risky investment, since Gianni Versace's lace hold-ups were among the prettiest and the sexiest items shown at last month's spring fashion shows. Without Lycra clinging fiercely to thigh and calf, they would either have been gathering themselves fetchingly around the models' ankles or leaving elastic welts around their thighs. There is so much in modern dress that would have been impossible without this particular by-product of the petro-chemical industry. Its initial ambitions, however, were modest.
In 1949 a young chemist, Dr Joe Shivers, was assigned to Du Pont's priority project: creating a fabric to displace rubber, a fabric from which a better, more comfortable corset might be constructed. It took him nearly ten years and, in 1958,
a Du Pont computer programmed to invent new product names settled on Lycra as a likely label.
Lycra is a synthetic elastomer fibre, generically known as spandex, which changes shape under pressure and snaps back to its original shape when the pressure is removed. The latter characteristic is called recovery and is an important factor in the list of qualities that make a fabric well-behaved and looking good.
At that point, however, Joe Shivers was more interested in Lycra's compulsion to snap back against the pressure. The better girdle, the light, flexible roll-on, and the better bra were his accomplishment. In fact, by the middle of the next decade, women were shucking off their roll-ons in favour of tights and a little later they took to burning their bras.
But Lycra was to have a lasting and unchallenged role to play in the swimwear industry. Almost every swimsuit has enough Lycra to stretch, when unravelled, between seven and eight miles.
It was a small leap of the imagination from swimwear to other active sportswear. In any area of human exertion where performance and comfort could be improved by firm support or a sleek, aerodynamically efficient profile, spandex - of which Lycra remains overwhelmingly brand leader - was able to give a garment an edge.
Cycling shorts, leotards and exercise tights, dancers' practice gear, athletic kit, wrestlers' and boxers' underpants, track suits and jodhpurs; all felt and performed better with a hint of Lycra and all, most importantly, looked sexier.
For while the runner or the dancer might have appreciated the clothes for their lack of wind resistance or their unchafing suppleness, the onlooker could not help but notice the skin-tight, body-displaying fit.
It was a surprise only to the unimaginative when garments designed for track and field began appearing on the disco floor and, very quickly, on the streets frequented by the world's more fashion-conscious youth. The international fashion designers, close observers of those streets, loved the youthful confidence of it, the jaunty swagger of leggings, the sinuous self-consciousness of the tiny tight dress, the easy, rib-hugging comfort of the clingy body. Lycra and its children really did epitomise the rather aggressive flaunt-it mood of the 1980s.
Du Pont, however, claim to have moved on. 'We have moved,' says Anette Bogstad, 'from functionality to comfort and freedom of movement, to sleekness. Apart from support tights, Lycra has only been used in hosiery since the late Eighties. Now, purely nylon lines are simply dying off. Women are used to non-bagging, wrinkle-free stockings.'
Last year, the corset-effect tights, most spectacularly launched by American designer Donna Karan as Bodyshapers, were what everyone was talking about and trying on. They really did make you thinner but, by and large, left cold the generations who had never known a girdle.
But the inventors of Lycra have been busily exploring other areas. They have long argued for a small percentage of the yarn in fabrics intended to drape, float or flow. That recovery capability imparts new life to soft, potentially saggy fabric and adds a sensuousness to the their handle. Current experiments also show that Lycra's determination to snap back reduces linen's creasability which deters many people from wearing it. At the recent Premier Vision trade exhibition of textiles in Paris there were between 1,400 and 1,800 different fabrics - from lace to boiled wool, from chiffon to tweed - all containing a discreet 2 per cent of Lycra.
Then there are shoes. Used either in fabric shoes or as a glued-in lining for leather shoes, Lycra improves fit and comfort. Marks & Spencer has already introduced a first generation of friendlier shoes. And in disposable nappies and incontinence pads (a growth market thanks to the ageing population) Lycra is much easier on the vulnerable chafe areas than is elastic.
Cotton-Lycra underpants for men promise to be big. 'I did a test on my husband,' says Anette.
'I bought him one pair of cotton pants with Lycra, one without and asked him to choose. He didn't hesitate to choose the ones with. He said the fabric was softer.' But tights for men - working name: mannyhose - although allegedly a hit with cowboys, skiers and Nautilus posers, are thought to have limited appeal.
A one-day exhibition of new design, The Contemporaries: Lycra In New Movements, is being held on Wednesday at the Imagination Gallery, 25 Store Street, South Crescent, London WC1. The exhibition is for trade and press only, but 'Independent on Sunday' readers carrying a copy of this newspaper can visit between 3pm and 4pm.