The humble knitted sweater vest has received more than its fair share of derision. Too nerdy, too preppy, too pointless, too Chandler Bing-y. And yet the sweater vest, which first appeared as a menswear piece around 1907 when an American football team decided to chop the sleeves off a sweater, is a trend that won’t die. Worn by everyone from US President Herbert Hoover in the 1930s to Cher Horowitz in the ’90s film Clueless and Jennifer Lopez earlier this month, like all good things the sweater vest continues to reinvent itself. Even if you last associated it with your secondary school geography teacher or every member of your grandpa’s golf club, make no mistake, the sweater vest has made a triumphant return. Proof that “grandpa chic” is having a moment (other than, say, the ugly hiking sandals, cardigans and Bermuda shorts you and pops may currently be sporting) can be found in recent seasons in which the likes of Gucci, Prada, Tory Burch , Louis Vuitton and more all experimented with the sweater vest. For Louis Vuitton spring/summer 2021, Nicolas Ghesquière sent a boxy patterned version down the catwalk, while Stuart Vevers at Coach has a playful version with an intarsia knit featuring a horse and carriage motif. Cool girl brands such as Frankie Shop and Danish label Ganni have iterations – the former a slouchy and oversized cable knit spotted all over Instagram, the latter a sweet and feminine cashmere number with statement embellished buttons. Ganni creative director Ditte Reffstrup is a long-time fan of the style. “I love the grandpa-cool look. It’s a bit preppy and ’90s, but I love how it contrasts with dresses and more sporty elements,” she says. “For me it’s all about creating an interesting balance full of fun and personality.” This sense of playing with proportion and personal style is easy to see on social media, with fashion influencers and editors such as Pernille Teisbaek and Tamu McPherson showing off their take on the style (while TikTok-ers are going further, offering styling challenges and tips on how to make your own). The hashtag #sweatervest has been used 78,000 times on Instagram. View this post on Instagram A post shared by All the Pretty Birds (@tamumcpherson) It’s impossible not to mention the Princess Diana effect too. Her fondness for sweater vests in her sweet kindergarten teacher phase was faithfully captured in the Netflix series The Crown . Then there’s pop star Harry Styles, who probably deserves some kind of medal for services to the advancement of sweater vests. His impressive wardrobe of sweater vests includes joyful sheep- and polka-dot-printed ones that he’s worn with wide-legged trousers and long-sleeve shirts in a look that’s part dandy and part nobody-else-dresses-like-him. Styles is also championing the return of argyle print this year, wearing, yes, a sweater vest, with the print in the video for his new song Treat People With Kindness (a fun aside: his rumoured new girlfriend, Olivia Wilde, was also just snapped in an argyle sweater too). Frankie Shop founder Gaëlle Drevet loves how the sweater vest seems nondescript but actually packs a lot of punch. “This style is simple but still special, not complicated but still interesting, and masculine-inspired with feminine touches – like its drop shoulders. Essentially, these qualities are true of any signature Frankie style, and the ones that we find are most beloved by our customers,” she says. “The variety of ways to style it also contributes to its popularity, since you can throw it over a tee while lounging at home, or pair it with a tailored shirt and trousers if you want to look put together, but still comfortable. It really fits people‘s lifestyles at this particular moment.” As for what’s driving the trend, as website Vox noted, sweater vests have long been a mainstay in the K-pop universe and, as British Vogue pointed out, K-pop is increasingly becoming a major influence on fashion trends and its stars a front-row fixture at fashion shows. Then there’s the cosy nostalgia factor. Sweater vests were especially popular in the ’90s and early 2000s, decades that, given the times we’re currently living in , seem almost preposterously simple. Besides, the ’90s have remained a constant source of fashion catnip. That you could buy a sweater vest from new season Tory Burch or a vintage store (or indeed raid grandpa’s wardrobe for one of his grooviest) adds to the appeal too. As the McKinsey/Business of Fashion State of Fashion 2021 report notes, sustainability and the “circular economy” (that is, reusing, repurposing and rewearing) is set to become increasingly important to consumers and the fashion industry. Ultimately, the real kicker for the sweater vest, with its unlikely wide appeal and unexpected versatility, is that it provides ample opportunity for reinterpretation. They look as good paired with tailored high-waisted trousers as they do worn over a flouncy dress. It’s for this reason Reffstrup intends to keep on playing with the style at Ganni. “[I]t’s become such a classic style for us, especially the one with the diamanté buttons, that has something very sophisticated about it. But we’re always thinking of the new way to do things, we are ever evolving, so expect to see more unexpected shapes,” she says. Still not convinced? Just ask grandpa.