This is natural leather produced by the only domestic tanner who continues to insist on vegetable tanning to bring out the original texture of the leather. The leather is soaked for 20 days by moving it from a pit with a low concentration to a pit with a high concentration of tannin resin extracted from the bark of natural chestnut, oak, mimosa, and other trees, and each piece of leather is carefully finished by craftsmen without sparing any effort. In addition, it is an environmentally friendly material that filters sludge through large-scale wastewater treatment facilities to purify the water to a harmless state before returning it to the river, an essential part of the manufacturing process.