Wimples at Yves Saint Laurent

Why do nuns always look so good? It isn't the habit, it isn't even the forbidden fruit scenario – it's their wimples.

Stefano Pilati framed models' faces at Yves Saint Laurent's autumn collection in fluid black headdresses that cascaded down to their shoulders. He assured onlookers that the symbolism wasn't religious (despite many a rosary chain in sight) and it's true that headgear can be for heretics too.

Women were expected to cover their heads with hats or scarves until very recently. It derives from the same sense of temptress tresses that is behind the hijab; hiding one's hair used to be a matter of common decency, from Saxon snoods to Chanel's cloches.

Ironically though, there is something about the severe fluidity of a well-styled wimple that sets off even the blandest of faces to perfection. Every woman has the bone structure of a Modigliani when her hair is swept back in a scarf.

Anne Boleyn knew it when she instigated the sleek French hood in place of the more burdensome gabled style of the English court – which, when on, resembled nothing if not a cuckoo clock with a face in the middle.

There's an elegance to replacing your hair with carefully draped fabric – it won't frizz or misbehave for a start, and it recalls some of the poise of those centuries-old sitters for Vermeer and Memling, regal in their steepled veils.

Hatter Nasir Mazhar often shows wimples and hennins in his collections, which speak of modern-medieval elegance. Rick Owens too and Bruno Pieters use plain wimples in their darkly romantic shows to focus attention on the garments, rather than on more earthly pleasures.

A statement look as at home on the catwalk as it is in the convent - there can't be many of those.

Harriet Walker is a fashion writer at The Independent

Zoë Taylor has appeared in Le Gun, Bare Bones, Ambit and Dazed & Confused. She is currently working on her third graphic novella and an exhibition