Black, crispy, often flat and square - dried seaweed, known locally as gim - is a humble staple on everyday dining tables across South Korea. But as its global popularity grows, its rising prices are worrying gim-lovers nationwide.
Lee Hyang-ran has been selling gim for the past 47 years.
In the past, people from Western countries thought Koreans were eating something weird that looks like a piece of black paper, the vendor, who is in her 60s, says from a small market stall in central Seoul.
I never thought I'd be selling gim to them. But now, they all come here and buy it.
South Korea is known to be the world's largest producer and exporter of gim, supplying markets across Asia, North America, and Europe. Some even refer to the product as Korea's black semiconductor, a reference to South Korea's large share of the global semiconductor industry.
Exports have risen steadily in recent years - and in 2025, South Korea's dried seaweed exports hit a record US$1.13bn, according to the Korea Maritime Institute (KMI).
And as demand rises, so do prices.
Known locally as an affordable snack or ingredient, gim typically cost around 100 won ($0.06; £0.05) per sheet in 2024 - with the snack usually sold in bundles of 10 sheets or more, or around $0.60 per pack.
But last month, the price of one sheet of gim rose to above 150 won - a record high in the country.
Premium products now cost as much as 350 won per sheet, said Lee.
Kim Jaela, who's in her 30s, typically buys gim in bulk - about 500 small sheets at a time, enough to last her several months.
But she says this may need to change, considering how expensive gim has become.
Oh my, it really did get more expensive by a few dollars! Luckily, I can survive a few more weeks with two packs of gim, but if I see the same or higher price later, I probably won't restock, she said.
The worldwide appetite for gim reflects a growing global demand for Korean goods, driven by cultural influences like K-pop and K-dramas.
In 2023, US supermarket chain Trader Joe's Gimbap - a Korean rice roll wrapped in seaweed - went viral and was cleared off the shelves nationwide shortly after its launch.
I first learned about gim because it's a typical Korean food often seen in K-dramas, Miki, a 22-year-old visitor from Japan told the BBC.
Viola, a 60-year-old visitor from Brooklyn, New York, says she enjoys gim as a snack. I just pop it in my mouth like a potato chip, she said, adding that it feels like a healthier alternative.
Kim Namin, 29, runs a seasoned gim processing factory with a 30-year family history in Wando, an island in South Korea's southern waters known for abalone and seaweed production.
His factory purchases raw seaweed, grills it with oil and salt, and cuts it into the familiar rectangular sheets sold in stores. Over the past five years, most of their products have been exported globally.
However, many agree that increased growing global demand remains a major driver. In an effort to appease domestic consumers, companies - alongside the government - are taking steps to curb rising costs.
South Korea's Ministry of Oceans and Fisheries has pledged to closely monitor the situation to stabilize its price, and Korean food companies like Pulmone have plans to establish a land-based seaweed R&D center.
Back in Seoul, the market buzzes with tourists, and business is booming for Lee. Gim has been selling like hot cakes... the ones for making gimbap are especially popular, she says. I'm glad Korean gim is getting popular.
