Korea has been a global purveyor of many trends, from K-pop supergroup <a href="https://www.thenationalnews.com/lifestyle/food/the-bts-meal-has-come-to-mcdonald-s-in-the-uae-but-is-it-worth-the-hype-1.1234180">BTS x McDonald's</a> signature meal to <a href="https://www.thenationalnews.com/lifestyle/wellbeing/powder-power-in-skincare-all-you-need-to-know-about-the-latest-korean-beauty-trend-1.1011985">powder power</a> in cosmetics. The K-beauty scene is particularly pioneering and one hack that’s had everyone talking on TikTok lately is Jamsu. It's the make-up trick Dutch-Palestinian model <a href="https://www.thenationalnews.com/arts-culture/celebrities-stand-for-palestine-bella-hadid-joins-new-york-rally-jeremy-corbyn-speaks-in-london-and-leicester-city-s-fa-cup-tribute-1.1223578">Bella Hadid</a> once told Huda Kattan she swears by, while in Dubai for a Dior campaign. The technique rose to prominence in 2017, but has since been doing the rounds on social media as a number of beauty bloggers have tried and tested it. A recent post by Makeup by Alissia on TikTok even garnered more than half a million views. So what’s it all about? Jamsu is said to have been created as a way to deal with the humidity of Korean summers and promises to set your make-up and keep skin looking matte throughout the day. It’s particularly popular among those with oily skin. The word roughly translates to “to submerge”. It’s also been said to mean “to dive” or “to douse”. And that’s basically what it is. Once you’ve finished applying your base make-up, including any foundation or concealer, you need to apply translucent setting powder and then submerge your entire face in a bowl of cold water. Save any eye make-up, lipstick or eyebrows until later. You dunk your face for between 10 and 30 seconds, depending on your skin type, then pat dry with a towel. Maree Kinder, founder of online store Beauty & Seoul, told <em>Dazed</em> that Koreans mostly use the technique in the summer, when temperatures are hot and humid, to prevent make-up from fading throughout the day. It's believed the cold water allows the foundation to blend with the skin and create a matte effect. So does it work? After Hadid told Kattan about the trick, <a href="http://www.thenationalnews.com/lifestyle/luxury/huda-kattan-bares-all-i-grew-up-thinking-my-skin-wasn-t-light-enough-which-wasn-t-right-1.991680">the beauty mogul</a> tried it and uploaded a video on her YouTube channel, saying "the overall result is that your face looks airbrushed, and you get a super matte finish. “I’m not sure if it’s the best thing to do for your skin every day,” she added, “but if you want your make-up to last all day, I would definitely give this a go.” Kattan advises people with dry skin (like her) do it for 10 to 15 seconds, while those with oily skin can dunk for 15 to 30 seconds. More recently, make-up artist Georgia Dyer said on TikTok: “My skin looks so nice. My make-up has all melted together, you need to try this.” Alissia said: “My skin looks flawless.” She posted another video after wearing her make-up for nine hours. “No, I don’t have a beauty filter on … It looks pretty good. I’m kind of impressed.” Another content creator called Judy wore hers for eight hours, and even fit in a gym session. Her verdict? “I think it held up pretty well. I’m not matte, but I’m not super oily. I think I have a good glow going on. I quite like it.”