Tanning method

If the skin (original skin) of the peeled meat is left for a long time, it will rot, and if it dries, it will become hard. To avoid this situation, a series of operations called tanning involves removing oil, dirt, and unwanted parts to make it corrosion-resistant, heat-resistant, and flexible. Generally speaking, what is peeled off from animals is called skin, and what is tanned is called leather. There are many methods of tanning, roughly divided into tannin tanning and chrome tanning. Tannin tanning (plant-based)
It refers to the method of tanning using tannins (with astringent taste) from plants, which has been used since ancient times. Leather tanned with tannins is also known as astringent or smooth leather, with a relatively hard texture and elasticity. Before dyeing, it is a light brown tannin that easily absorbs oil. During use, it turns yellow white due to acidification and sun exposure. After combustion, no harmful substances will be produced. Chrome tanning (mineral based)
The method of tanning using chromium salts. Time and cost do not need to be as long or high as tannin tanning, making it suitable for mass production. Chrome tanned leather has elasticity, heat resistance, and stretchability, and because it is relatively soft, it is also suitable for machine sewing. Before dyeing, it is a light blue gray color, which produces better color during dyeing and is not easily discolored. After combustion, toxic hexavalent chromium will be produced, and attention should be paid when handling it.