They say they use top layer leather, but what kind of high-end product is it?

Hong Kong Lee Kee Handmade Leather Goods

Exquisite leather bags are the favorite of many women. When you go out, carry a delicate leather bag, and your whole temperament seems to be sublimated. In order to attract customers, merchants claim that their leather bags are made of top-grain leather. What is the top layer of skin? Why do businesses need to vigorously promote it? Let's explore the mysteries together.

To make clothes, you must use “real” leather

From primitive people's "eating meat and sleeping on skins" to the assembly operations of modern leather processing factories, the history of human civilization has always been accompanied by the utilization of animal skins.

Whether in prehistoric times to keep out the cold and cover up shame, or in modern society to highlight status and temperament, clothing made of genuine leather has always been sought after. The "authentic" here not only shows that the material does come from the body of an animal and is not a synthetic plastic, but also There is a deeper meaning: they belong to the dermal layer.

The skin of most vertebrates, including us humans, is divided into two layers. The layer immediately below the hairs, that is, the layer that can be seen and touched, is called the epidermis. The part below the epidermis is called the dermis. The two layers of skin are Together with the fat and muscles below, it protects our bones and internal organs.

Due to the thin skin, only genuine leather can be used for clothing, hats and shoes. The dermis is divided into two parts from top to bottom: the "papillary layer" and the "reticular layer". If you get a piece of skin and remove the hair and epidermis, you can touch the nipple layer. The nipple layer is also called the "grain layer", so named because it is covered with granular protrusions that resemble nipples. The nipple layer downward is called the reticular layer, and the reticular layer is also called the "meat layer". It is densely covered with a protein fiber network filled with water, fat, blood vessels and other substances.

Why use “top layer of skin”?

In the dictionary, "head" has the first meaning. However, the material used in the so-called "top layer leather" leather bag is not just the top layer of genuine leather, but leather composed of the papillary layer and the mesh layer. The opposite is the "second skin" with only the reticular layer left.

Why do businesses promote top skin? This is about the difference between the papillary layer and the reticular layer. Although both the papillary layer and the reticular layer contain a large amount of collagen, their characteristics are completely different: the collagen in the papillary layer is thin and dense, strong and wear-resistant; the collagen in the reticular layer is thick and sparse, interspersed with each other. Fat and muscle, soft and hard, with excellent elasticity.

Therefore, a leather bag made of the first layer of leather has both the strength and wear resistance of the papillary layer of dermis and the good elasticity of the reticular layer of dermis, and feels better to the touch; while a leather bag made of second-layer leather has good elasticity to the touch. However, due to the sparse collagen and poor wear resistance, it cannot be used. Comparing the two, of course the first-layer leather bag with more comprehensive features is more marketable.

Which “skin” is best to use?

As the saying goes, "The nine sons of a dragon are all different." Naturally, different parts of the same animal skin have different advantages and disadvantages. Research has found that the skin on the back and buttocks is the most suitable for making leather. First, because these parts do not move often and the collagen in them is arranged neatly, so it feels smooth and firm; second, because the skin here is thicker, the leather produced is also It's more durable.

How to transform skin

After finding the best leather, the next task is to transform it. The two core steps in making leather are "degreasing" which allows the hide to be preserved longer, and the other is "tanning" which makes the hide softer.

Fat removal, as the name suggests, is the removal of fat. Since the fat in the dermis is filled with collagen fibers, it needs to be removed with the help of chemicals. In ancient times, people soaked animal hides in water containing alkaline substances such as baking soda and slaked lime to decompose oil; in modern times, with the fast pace of life, tanneries, in addition to continuing to use chemical reagents with stronger penetrating capabilities, also use Lipase acts as a catalyst to speed up decomposition.

Fat removal deals with fat, while tanning deals with the collagen in the skin. Most of the collagen in the dermis is fibrous. Each collagen is composed of three amino acid chains mixed together like a rope. The amino acid chains in different collagens are intertwined to form a tough fiber network. The function of tanning is to allow various tanning agents to penetrate into the fiber network, destroy the structure inside, and then assist with external force factors such as rubbing and beating to make the gaps in the network larger, thus changing the texture of the rawhide.

A small leather bag actually contains so much knowledge. Doesn’t it make you feel taller when you put it on?

Come and buy your favorite bags~
Li Ji handmade leather , Li Ji original handmade leather , first layer cowhide
There are all kinds of bags here ~