From candy girl to sailor boy, this season has seen a strong appearance from our perennial favourite - stripes. Forget camouflage prints and Grecian drapery - only a few trends are going to make it to the end of the summer season, and right up there in the lead is stripes. They made a strong start to the season, thanks to candy-girl collections from Marc by Marc Jacobs and Marni. And this autumn sees pinstripes - in many different colour combinations - making a comeback.

The secret to the staying power of stripes is their adaptability. They are the social chameleon of fashion, slipping into punk style, nautical themes, black-and-white graphic looks and American college-girl cuteness. They straddled the fashion capitals at the spring/summer 2001 shows, uniting a miscellany of designers under one flag. From Dries Van Noten and Viktor & Rolf, via Marni and Missoni, Matthew Williamson and Clements Ribeiro, to Marc Jacobs and Wink, stripes have been the common thread.

The stripe may be the insignia of this particular summer, but there are a handful of designers who always step in line. Sonia Rykiel is the patron saint of stripy clothes and has made the exploration of knitted stripes her life's work. "Whether they're broken or angled, wide or narrow, bi-colour or multicoloured," says Rykiel, "stripes are indispensable to me." At Rykiel's spring/summer catwalk show, a finale of a dozen striped knit mini-dresses in every colour of the spectrum proved that, although others might dabble, the stripe belongs to her.

Stripes also count Paul Smith and Jean Paul Gaultier as stalwart supporters who have made them a signature for their labels. Both Smith's English Eccentric version of multicoloured vertical stripes and Gautier's traditional navy-and-white Breton pattern are having their time in the sun. They chose their trademarks well, because stripes, more than polka dots or houndstooth check, are a classic. That's why they don't suffer for appearing late in the season.

In their simplest form, stripes can cast off any designer reference to Fifties beachwear or Sixties Art, and only seem clean and modern. The nautical feel of a Breton shirt - Coco Chanel's favoured resort-wear in the Thirties - has dominated spring fashion, but it's also the version of stripes most suited to high summer. Unless you sail yachts or ridicule Frenchmen for a living, this isn't workwear. There's nothing uptight about the sugar-dusted narrow stripes seen at Marni and Vivienne Westwood.

Whether it's deckchairs or yachting, French Riviera style or Neapolitan ice-cream that inspires the thought, they're for the most part associated with casual clothes worn on holiday. They are the trend that loves to travel, while black leather bondage dresses and Fifties frou-frou skirts are left behind to house-sit (both very good at scaring off burglars). Even when stripes are worn on home turf, a sense of the leisured lifestyle is bound to overcome you.

The only fretful thought that might disturb your calm is the question of whether they flatter. Stripes, especially horizontal bands, are much maligned for their, let's just say, broadening qualities. But there are ways to prevent this stylistic hiccup. An asymmetric-shaped top will break up any unwanted effect of width with a slice of brown shoulder. Its variable width of stripe, also seen at Prada and Valentino, is much kinder than a regular stripe. Diagonal or slightly askew horizontal stripes, like those used by Costume National and Louis Vuitton, will only show off the curves that you want them to.

Sonia Rykiel offers some advice to the cautious wearer. "Just don't wear them too close to your face," she says, "and wear a necklace or a scarf around the neck. Or wear a striped scarf, contrasting with a plainer garment." If you just want to paddle in the shallow end of this trend, stripe an accessory: shoes, bags and corsages have all earned theirs, especially if they feature striped ribbons or rosettes. So, for now, put that black wool jacket back on the rail. August fashion doesn't have to be a sweaty hassle of sales and premature knitwear. Stripes are the easy-going summer trend, happy to do whatever you want them to do. The perfect holiday companion.