Classified by purpose, leather is used for daily life, national defense, industry and agriculture, and cultural and sports goods; According to the tanning method, it can be divided into chrome tanned leather, vegetable tanned leather, oil tanned leather, aldehyde tanned leather, and combination tanned leather. In addition, it can also be divided into light leather and heavy leather. Leather commonly used for shoe uppers, clothing, gloves, etc., is called light leather and is measured by area; Leather made from thicker animal skins using vegetable tanning agents or a combination of tanning agents, used for the inner and outer soles of leather shoes and industrial accessories, is called heavy leather and is measured by weight.

According to animal species, there are mainly pig leather, cow leather, sheep leather, horse leather, donkey leather, and kangaroo leather, as well as a small amount of fish leather, reptile leather, amphibian leather, ostrich leather, etc. Among them, cowhide leather is divided into yellow cattle leather, buffalo leather, yak leather, and yak leather; Sheepskin leather is divided into sheepskin leather and goat leather.

There are two types of leather: top layer leather and second layer leather, with the top layer leather consisting of full grain leather and finished leather; Second layer leather includes pig second layer leather and cow second layer leather. Among the main types of leather, yellow cattle leather and sheep leather have a flat and fine surface, small pores, a dense and compact internal structure, and a leather body with good fullness and elasticity, as well as good physical properties. Therefore, high-quality yellow cowhide and sheepskin are generally used as leather materials for * products, and their prices are relatively high among bulk leather.

Classified by skin and leather: "Genuine leather" is a common term in the leather products market, and is a customary term used by people to distinguish natural leather from synthetic leather. In the minds of consumers, 'genuine leather' also has a non fake meaning. Animal leather is a type of natural leather, commonly known as genuine leather. It is a leather material made from animal (raw skin) tanned and processed by leather factories, with various characteristics, strengths, textures, colors, and patterns. It is an essential material for modern leather products.

The processing of animal leather is very complex, and it needs to go through dozens of steps to make finished leather: raw leather - soaking in water - removing flesh - degreasing - depilation - soaking in alkali - expanding - removing ash - softening - soaking in acid - tanning - layering - smoothing - retanning - neutralization - dyeing - oiling - filling - drying - finishing - coating - finished leather. There are also many types of leather, including sheep leather, cow leather, horse leather, snake leather, pig leather, crocodile leather, etc. According to their properties, they can be further divided into two-layer leather, full grain leather, suede leather, modified surface leather, laminated leather, composite leather, and decorative sectional leather.

Among them, cowhide, sheepskin, and pigskin are the three major types of leather used in leather production.

Regenerated leather is made by crushing the waste of various animal skins and dermis and blending chemical raw materials. Its surface processing technology is the same as that of genuine leather for facelift and embossed leather. Its characteristics are that the edges of the leather are relatively neat, the utilization rate is high, and the price is cheap; However, the leather body is generally thick and has poor strength, making it only suitable for producing standardized products such as affordable document boxes, pull rod bags, and golf club covers, as well as affordable belts. The longitudinal fiber structure is uniform and consistent, and the solidification effect of the mixed fibers of the fluid can be recognized.

Artificial leather, also known as imitation leather or rubber material, is made of materials such as PVC and PU