There are many traditional techniques that are still in use in present day Snow Country. One of the most visually stunning that we have witnessed recently is Yukisarashi, which is the process of laying lengths of kimono material out on the snow to be bleached.
Weaving has a long history in Snow Country with evidence of material woven from plant fibres dating back to Jomon times. Shiozawa has long been a important town for textile manufacture and the cloth from this region has been listed as an intangible cultural heritage by UNESCO.
Part of the process of the cloth manufacture in the region has been laying the material out on the snow in the spring sunlight to bleach. The action of the snow and the ultraviolet light is supposed to release ozone which bleaches the material and also cleans it. This process is only effective with cloth that has been made from plant-based material. It would not work for silk. The ingenuity of craftsmen back in the day harnessing the power of the snow and the sun is really something to be admired (especially as you can get washing machines now that claim to use ozone for cleaning!)
The thread from the cloth has been made from splitting plant fibre by hand, and it is then woven by a skilled artisan into beautiful material. This bleaching process is another step in this labour intensive production method, and it is easy to see why this material is held in such high regard and commands a high price. We can only hope that techniques like this continue to be used.