Korean beauty, AKA K-beauty, exploded circa 2015, but its second wave is tidal. There are a dozen or more K-beauty boutiques (all heaving) within a stone’s throw of Leicester Square in London. A branch of Korean beauty boutique Pure Seoul recently opened near my home in Brighton, stocking a dizzying array of niche skincare and makeup products – cushion foundations, feather-light sunscreen, jelly moisturisers and eleventy billion varieties of face mask.

Even Boots has stated that Korean skincare accounts for more than a tenth of its total skincare sales, with a Korean product sold every 30 seconds. Brands like Laneige (pictured), famous for excellent hydrating products and fun lipbalms, Beauty of Joseon (impeccable sunscreens) and COSRX (specialising in sensitive and acne-prone skin) are available on the UK high street.

So what defines K-beauty, aside from its Korean manufacture? Barrier care is a big piece of the puzzle – using products to cosset, protect and keep in balance the skin’s protective barrier, with gentle ingredients like squalane, peptides and niacinamide, rather than more aggressive active ingredients.

Texture is another giveaway. Korean products are what industry insiders call “cosmetically elegant formulations”, a fancy way of saying they feel nice – fine, ungreasy, easily absorbed.

Finally, they “flood” the skin with many layers of humectants such as glycerine and hyaluronic acid to give the skin a glassy appearance.

If all this sounds like a lot, that’s because it is. And why the craze for Korean skincare in the west represents such a step-change. Our cultural norm has been to speed through skincare, doing as much as you can with as little as possible. K-beauty requires time and a more ritualistic approach – double cleansing, and several layers of moisture in the form of mists, essences, serums, lotions and sun protection.

A brand needn’t originate in Korea to be Korean in style, of course. Then I Met You’s founder is Korean-American, but was inspired by five years living in South Korea. Her Living Cleansing Balm (from £14) – a sumptuous but ungreasy, mango-hued makeup remover – is among the best I’ve tried.

British brand Vieve’s new Super Skin Nova (£39), a glowy moisturising primer balm with a glassy finish (gorgeous worn alone on no-makeup days, as well as under foundation to give it more life), performs just like a Korean formula because it was developed and made there. It sold out on launch, but it’s worth waiting for the restock.