Vinalon is a fabric that cane be made from limestone.
Due to the cold weather and thus lack of efficiently in producing cotton and wool, vinalon has been a popular fabric to make clothes until recent.
The technology was originally developed in Japan in 1930s, and later brought to Korea.
It was known as "Juche Fiber" under Kim Il Sung's ambitious promotion.
Several vinalon factories were established, and even "Vinalon Cities".
When Russia decreased aid to North Korea in 1960s, vinalon was a major product for their self-reliance. North Koreans called vinalon “the King of Fibres” and even featured it in cartoons.
Not many people wear vinalon clothes in the world today, but it is known that vinalon clothes are resistant. Kim Sun-hee, a North Korean defector who attended an opening ceremony of a vinalon plant said: “Inside the factory I saw pink and red jackets. Even after 15 years, the vinalon jackets did not get frayed, although the colors could change a bit.”
However, vinalon clothes have some fatal drawbacks. They are difficult to dye, and quite uncomfortable to wear, especially after getting wet.
Today vinalon is more applied to ropes, nets, cements etc., although Kim Jong Un still holds the ambition to mass-produce the fabric again.
There is an interesting article about this:
https://www.reuters.com/investigates/special-report/northkorea-vinalon/