Horizontal stripes: the perfect ratio

Brigitte Bardot in the classic Breton top. Photograph: Sunset Boulevard/Corbis

While obviously, obviously, the debate over whether horizontal stripes are flattering or not should be utterly moot, it’s still discussed with abject fascination. Daft, really, especially in light of a new theory by costume designer Alison Freer, who has written a book in which she helpfully stubs out the debate all together. In the book, How To Get Dressed (out today), Freer claims that when deployed in the correct proportions – 90 cream to 10 dark – horizontal stripes create a “balanced illusion”.

The irony is that, like many trends, striped tops (specifically the Breton top, which is the mother of them all) were born and worn out of functionality. The official uniform of navy seamen in Brittany in the 19^th century, the top’s slash neck made it easy to slip on and off. The 21 stripes – one for each of Napoleon’s victories – were also key, as were the contrasting colours, which made the wearer relatively visible if they fell overboard: a sort of precursor to hi vis. Later appropriated by Coco Chanel in the early 20th century as a two-fingers to corsets (and then by all on the high street), the Breton top is arguably the reason that horizontal stripes remain a fashion fixture.

But back to Freer’s theory. Stripe-gate has three schools of thought: one stems from a phenomenon known as the Helmholtz illusion, which found that a square or rectangle composed of horizontal lines appears taller and narrower than an identical square or rectangle made up of vertical lines. The other, more prevalent, popular belief is that they widen the wearer because our eyes are drawn to the lateral direction of the lines. The third is that no one really cares but, science aside, 90:10 is still a delicate, minimal approach to striping in general. With that in mind, here are five of the best 90:10 (ish) striped looks.

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Max Mara T-Shirt, £205, Matches. Photograph: Matches

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LemLem Abara striped cotton-blend gauze jumpsuit, £225, Net-a-Porter. Photograph: Net-a-Porter

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Striped swimsuit, £19.99, Zara. Photograph: Zara

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Wood Wood Striped Dress, £95, Asos. Photograph: Asos

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Striped funnel-neck crop sweater, £30, Topshop. Photograph: Topshop

How to Get Dressed: A Costume Designer’s Secrets for Making Your Clothes Look, Fit, and Feel Amazing by Alison Freer is out today, published by Ten Speed Press