➊ Not "leather" is enough

You probably don't know that there is a machine called a skin machine.

A cow with a thickness of 4-5mm, a powerful machine can produce as many as 8 layers.

Of course, this is generally not the case, the most common is the film into two layers -

The top layer is the top layer of skin, including a dense dermis layer and a relatively loose fibrous tissue layer.

The lower layer of skin below, there is no dermis layer, only the fibrous tissue layer.

The second layer of leather also has the characteristics of leather. After the surface coating material is pressed on the pattern, it does not seem to be different, but its wear resistance is poor, and it is easy to expose the bottom and break. Some poor quality coated suede skin is even toxic.

Of course, there are also two-layer skins with good raw materials and craftsmanship, which are very wear-resistant.

Therefore, the treated two-layer skin is difficult for ordinary people to distinguish.

The second layer of skin is still conscience, some so-called "leather", even the lower corners are pressed.

This is one of the most common "leather" traps.

➋ different fate cattle and cattle

There used to be two cows, one born in rural Africa and one born in a European farm.

This cow in Africa is not good enough to eat and live, the skin is not so smooth, and it is common for a bite to be bitten by a calf.

The European cow grows freely in a picturesque environment every day. The environment is less worms and the skin is firm and smooth.

After the two cows grow up, they are peeled and fleshed to complete the mission.

Naturally, the leather of Africa, the cortex is loose and covered with scars.

Of course, it is also used for polishing smooth, sprayed with chemical materials, and even embossed.

(that is, semi-grain leather or shaving leather)

The European cowhide with clear pores, smooth and firm.

In addition to the basic tanning process, it does not require excessive processing and comes with beautiful attributes.

(This is the legendary full grain leather)

This example is just to say that the difference between cowhide in different places is very big.

The degree of commercial farming in the United States is high, and the quality of cowhide is stable. It is the first big cow exporter, but it is not the best.

European animal husbandry is developed, the climate is suitable, there are few mosquitoes and calves, and the scars of cattle and sheepskin are of low quality. Basically all the top leathers are produced in Europe, especially France and Italy.

In addition, like Argentina, Mexico, etc., mainly produces low-grade cowhide.

Deliberately found two skins for comparison, the top is the quality of the British horse leather, the following is the quality of the vegetable tanned leather (original unknown).

Look at the cut surface, although the skin is cut off some of the skin, still tight and thick, smooth meat.

The other one is thinner than the horse, and the flesh has been loose.

The type and size of the cow also determines the quality of the skin.

The cowhide we are talking about is usually yellow cowhide. Buffalo is heavy and rarely used for bags.

Because of pregnancy, fat and cortical loosening, bull hides are definitely better than cow hides.

The calfskins within two years old have small and clear pores, strong elasticity and strong endurance. The leather is fine and feels good, and the size is much smaller than that of adult cows. This is more precious and the price is extremely high.

There is also a type of fetal cowhide, which is meant to mean calfskin in the dead belly, which is extremely rare. However, the cow hides that the merchants say now refer to the younger calfskin.

➌ Good skin embryo + good craft = "cow" skin

In addition to the cow itself, the craft is also the focus.

Leather leather, peeled off is "raw skin", after processing into "leather" (excluding artificial leather)

This process, called "tank", is a process in which collagen fibers are changed, unwanted components are removed, and they are dry, soft, and non-perishable.

[Tanning process] is very complicated, there are two common types:

Vegetable tanned leather -

Domestically, it is called tree cream and rubber.

It is a leather that is slowly smashed from raw hides using vegetable tanning agents.

(Plant tanning agents are tannins, plant polyphenols, etc. contained in plants, which can turn raw hides into leather.)

Vegetable tanned leather is a kind of color-changing leather. As the sun, body temperature and body oil moisturize, the color of the leather will gradually deepen, from flesh color to honey color and even caramel color.

This process of raising the skin is similar to the wenwan "pasting" and is very fun.