K-fashion's lightweight craze: the thinner, the better

Demand for lightweight, breathable fabrics is rising as midday heat persists even past the traditional start of autumn.

Fashion brands are moving beyond simple cooling functions and focusing on fabric composition and weave, according to industry sources Tuesday. Trimming the weight and thickness of materials has had a direct impact on sales.

Heavy denim has gone on a diet. Hazzys is a prime example. This summer, the brand expanded its lineup of 7-to-8-ounce Coolmax denim and denim-like linen products — lighter than standard denim — by 30 percent compared with last year. Sales of those products rose 47 percent year-on-year in June and 28 percent last month.

In menswear, casual brand TNGT introduced a "lightweight denim" line made with thin summer fabric. The initial stock sold out, and a reorder has since reached an 84 percent sell-through rate.

Shorts have also entered the fabric race. TNGT more than doubled the number of shorts styles and items this year compared with last year, and shorts sales for the spring-summer 2026 season rose roughly fivefold from the previous season. Its seersucker "Kinoshita" shorts sold out of the main stock and went into reorder; the sell-through rate stood at 80 percent as of early this month.

Seersucker, with its puckered texture that reduces contact with the skin, has become a staple of summer comfort wear and a fixture in sports brand collections. K2's "Siwonseoker" cooling collection, launched last year, saw sales climb 30 percent this year over the previous year.

Lightness is also driving innovation in weave. Crochet shirts, which improve air circulation through their open construction, have emerged as a late-summer staple — British Vogue named the crochet shirt one of the defining items of this summer. Atté Vanessa Bruno expanded its knit collection featuring loosely woven crochet fabric blended with linen yarn, adding nine new products this year compared with last year. Sales rose 170 percent year-on-year.

Raffia, a material derived from the raffia palm, is also drawing attention as a late-summer fashion item. Vanessa Bruno doubled its raffia bag styles and stock this year compared with last year, and a raffia bag charm released alongside the collection sold out within a month of launch.

"As the heat stretches longer than in previous years, we're seeing changes in the materials and designs used for summer," an industry official said. "Demand is growing for products that use lightweight, breathable fabrics and weaves — not just cooling technology."