Until recently, the only people wearing waistcoats were naff boy bands, fruity jazz musicians and your kid brother.
But in the past few months, some of the globe's best-dressed gents have decided to walk the red carpet in waistcoats, either with matching trousers or as part of a three-piece suit.
And they've looked good doing it. Turns out the waistcoat is a remarkably versatile garment that can effectively dress up or dress down almost any outfit – if you're careful.
The king of this nascent trend is Hollywood star Ryan Reynolds, who looked incredibly dapper when he fronted a recent film premiere in Tokyo wearing a checkered grey waistcoat and a crisp white shirt rolled up to the elbows.
Since then, he's rarely been seen without a vest of various sorts. A few weeks ago, in New York City, he rocked an extravagant three-piece suit in burgundy moleskin, featuring a low-cut waistcoat with two rows of buttons.
Reynolds isn't the only one opting for a three-piece suit this season. After years of men going casual on red carpets, it seems the pendulum is finally swinging back towards 'proper' formalwear: witness Keanu Reeves and David Beckham looking sharp in three-piece suits during their recent appearances.
The new summer uniform
As Reynolds, Reeves and Beckham demonstrate, a strategically deployed waistcoat can elevate a regular suit and project a real sense of sophistication, without necessarily coming off as stuffy or over-the-top.
But here in Australia, summer is well-and-truly upon us. The prospect of wearing a three-piece suit to a sweltering summer soirée is hardly appealing.
Perhaps that's why, at a recent social event that Stitched Up attended in Sydney, one of the best-dressed male guests was wearing a waistcoat without a jacket, Ryan Reynolds-style. He looked every bit the gentleman.
Rules of engagement
So, how did our fellow party guest deploy this somewhat daring style and not come off like a dork at a high-school formal.
First and foremost, he paired his navy pinstripe waistcoat with matching trousers, most likely from a three-piece suit. He simply left the suit-jacket at home. This gave the outfit a sense of purpose.
Secondly, he kept the rest of his ensemble simple – a classic white shirt with a smart black tie and black dress shoes – which helped him look like he wasn't trying too hard. (Bonus points for successfully pairing blue and black, a tricky combination.)
Thirdly, he rolled up his sleeves. If you're going to wear a waistcoat (i.e. a garment without arms) and no jacket, long shirtsleeves will look awkward. Trust us.
Look, waistcoats aren't for everyone. If the thought of wearing one triggers teenage flashbacks or simply makes you nervous, it's perfectly fine to let this trend pass you by.
If you have the nerve, however, why not don a waistcoat for the next garden party you're invited to? The results may pleasantly surprise you.
Just remember: never wear a waistcoat baggy or unbuttoned unless you want to look like an adolescent cinema usher.
Dan's writing on style, travel and more has appeared in The New York Times, the Australian Financial Review, Condé Nast Traveller and others. He is based in Sydney.
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Take a look at the gallery above to see some of the best waistcoats for fresh summer style.