Leather was one of the earliest human discoveries in history. The primitive man hunted animals for meat and would use their skin for making clothes, shoes, and even tents. Till today, it is considered one of the finest and luxurious materials that humans have ever used.
Despite it being around for such a long time, people don't know much about it in-depth except for the fact that it is leather, and it comes from animals. Let me tell you this; not all leather is created equal.
In this blog post, I am going to discuss leather in great detail. With topics like how the leather's prepared, what are the different types of leather, how you can tell them apart, and most importantly, which leather type is the best one
So let's dive deep into it. Shall we?
What is Leather?
Leather is a natural material obtained when raw animal hides are processed using chemical or natural extracts in specialized processing units called tanneries. The history of leather tanning is very ancient and has evolved throughout the ages.
Raw hides are obtained from a variety of different animals; some examples of these animals are given below:
- Goat Hide (Garments, Gloves)
- Cow Hide (Wallets, Belts, Bags)
- Buffalo Hide (Garments, Belts Armor)
- Sheep Hide (Shoes, Accessories)
- Deer Hide (Footballs, Garments)
Properties of Leather
Leather is one of the most durable and sustainable materials around, which is why it's widely used in producing items like garments, bags, wallets, and even knife sheaths.
Some of the leather's properties that make it unique include:
- High resistance to fire
- Tear resistance
- Puncture proof
- High resistance to flexing
- High resistance to chemical exposure
- Good heat insulation
Why would we use leather when we have cheaper synthetic alternatives?
Apart from its distinct advantages like durability, resilience, and a wide variety of applications, leather is like a fine wine; it ages well over time. It forms a particular dense colored layer called the patina that gives it a great antique look over time.
Artificial Leather vs. Natural Leather
Artificial leather (also known as Faux Leather) is a leather made from a plastic base, which is then treated with wax or dye to create its color and texture. While artificial leather is a cheap alternative to natural leather, its properties don't even come close to the natural leather.
Below are some of the differences between faux (artificial) leather and natural leather.
How is Leather Made?
An animal hide is converted to finished leather via a specialized process called tanning. Contrary to popular belief, tanning for leather is not lying down under the sun with sunscreen on.
The process is carried out in plants called leather tanneries, where the hides go through various chemical and physical processes that impart the desirable strengths that make leather unique.
Let's discuss the tanning process in more detail.
Leather Tanning Process
What is Tanning?
Tanning is a process of converting the proteins of rawhide or skin into a stable material that will not putrefy over time when exposed to moisture and heat. Tanned material dries out and forms a flexible material suitable for various industrial and household usage.
The process of tanning involves the chemical cleaning of the hide, removal of skin and hair, drying, softening and finally dyeing to get that proper finished buffed out leather look that we all know (and love)
The purpose of tanning the rawhide is to make the leather less susceptible to degradation over time. A rawhide, when used without proper tanning, degrades overtime when it comes in contact with water, heat, or other harsh environments. It modifies the leather at a molecular level and helps maintain its durability and quality over a long period.
The below flowchart summarizes the stages and processes involved in the tanning process.
Types of Tanning
The process of tanning rawhide into finished leather is not new. The knowledge has been developed thousands of years ago and has been passed on from generation to generation and has evolved over time.
The tanning process can be classified into two main types based on the kinds of chemicals used in the process.
Chrome tanning is the most widely used process to obtain finished leather. The process starts with the washing of skin to remove dirt and other foreign agents, including bacteria that might have bound with the skin hair. Water with detergents is used during this process.
After the skin is washed, the next step is to remove the hair from the hide. The hides are soaked in Calcium Hydroxide (lime) based solution. The high pH of the lime solution helps remove the hair follicles. This process is followed by de-liming, where Ammonium Sulphate and Ammonium Chloride are used.
The hides are now clean from salts, hair, and other contaminants and ready for the tanning process.
In the next step, the hides are loaded into a drum with Chromium sulfate and other supporting mineral salts. When the tanning is complete, the hides are wet and blue, that is why they are called wet-blue. The wet-blue leather is then dried to remove the access water, inspected for any quality issues.
Next is to dye the leather to get a desired final color. The drying process happens inside the drums with water and dyes. After the dying process is complete, the leather is dried either in the air or using a vacuum section and then goes through the final finishing process.
The last step is the quality check to ensure everything is well under established quality standards.
Vegetable tanning is a more traditional form of tanning hides. Unlike Chrome tanning, it involves tanning agents from natural ingredients like the extracts of chestnuts, mimosa trees, and quebracho for the process. The process starts with the hide being salted and brought to the tanneries.
This is where the cutters help separate the leather into distinct sections (body, shoulders). The skins are then immersed in large wooden drums where they are thoroughly cleaned. Then the fleshing process is performed where the hair follicles and skin is removed.
After the hair removal, the master craftsmen soak the hides in water and tenants for 40 to 60 days. The dyeing and fattening processes also take place in the same drums/soaking pools at different times during the said period. After which the pressing and shaving help in removing the excess moisture on the skin.
Finally, the leather is dried and inspected for quality issues before being shipped. This process may be long, but it produces a more 'natural' looking leather with a very distinct aroma.
Chrome Tanning vs. Vegetable Tanning (The Difference)
The difference between both processes is defined below:
Is Chrome Tanning Environment Friendly?
The process of Chrome tanning involves the use of highly corrosive chemicals which produce toxic wastewater. If not properly treated, this waster water is pestilent for the environment.
To reduce the production cost, some tanning companies might not treat the wastewater and dump it in rivers or other water reservoirs, which impacts not just animal life but human life too.
At Aurochs, we take the environmental impacts of our operations very seriously. You can read more about our efforts to protect and safeguard the environment. Here.
Types of Leather
As I mentioned in the start, not all leather is created equally. Depending on the animal hide, the tanning process used, and the section of the hide, we can categories a finished leather into various types.
However, the one factor that directly impacts the quality, strength, and life of leather is the cross-section of the hide that has been used to produce the leather.
Why and how Leather is Split?
Naturally, animal hides are quite thick and not suitable for most practical uses. That's the reason it is split horizontally, making several layers of the same hide. Each layer has unique qualities and results in its kind of leather, which were are going to discuss in detail below.
The splitting of leather results in three main types of leather;
- Full Grain Leather
- Top Grain Leather
- Genuine Leather
Full Grain Leather
When the hide is split horizontally, the topmost layer just beneath the hair results in full-grain leather. It is the most durable and robust part of the animal hide and makes the highest quality leather.
FIBER ARRANGEMENT: The fibers on the top are arranged in criss-cross arrangement giving additional strength and wear & tear resistance to the leather.
PHYSICAL APPEARANCE: If you look at a full-grain leather closely with a naked eye or with a magnifying glass (recommended), you will notice the natural grainy surface of the leather.
These "grains" are the places where the hair follicles were attached to the skin, which were then removed during the tanning process. This is the primary identification of full-grain leather.
NATURAL IMPERFECTIONS: As the outermost layer of the skin is exposed to different environmental hazards like insect bites and cuts & bruises, it's natural to have imperfect skin at various places.
During production, these imperfections are either avoided or sometimes willfully included to give the resulting product a unique look. Although these imperfections can be removed by sanding or buffing the surface, it generally reduces the leather strength.
In some parts of the world, animals are raised in a controlled environment to reduce the risk of skin imperfections.
AGING OR PATINA: Full grain leather also develops a beautiful patina when used over time. Patina, which is a soft sheen that develops over full grain leather through exposure and usage, gives the leather a personality, character, and class. It is a sign of a high-quality leather revered by those who keep leather goods.
Top Grain Leather:
The Top Grain leather, also known as Corrected Leather, has had a couple of millimeters of the leather sanded and buffed with the intention of taking away imperfections. It's obtained from the middle portion of the animal's back.
FIBER ARRANGEMENT: The fibers on the top grain leather contain more densely packed fibers. This increases the leather's strength and endurance.
PHYSICAL APPEARANCE: Upon closer inspection, you will notice that the natural grainy feel of the leather is gone, and its replaced with a more uniform feel. This is the result of the leather being sanded and buffed during production.
NATURAL IMPERFECTIONS: During production and removal of imperfections, this type of leather is imprinted with an imitation grain to give it its signature uniform look despite reducing the strength and durability of the leather significantly.
AGING OR PATINA: Top grain leather overtime does not produce a patina like the full grain leather.
It's available in large quantities and is considered less expensive. This is because Top Grain leather comes from the more substantial portion of the leather, which is refined and is available more readily because of less damage to the hide.
Genuine leather does not mean good quality leather; instead, it's one of the lowest quality of leather around. Genuine leather or Suede Leather/Bicast is prepared from the lower section of the skin and has a lower resistance to wear and tear.
FIBER ARRANGEMENT: The fibers on the genuine leather have a parallel arrangement to them. This parallel arrangement significantly reduces the strength and wear resistance of the finished leather.
PHYSICAL APPEARANCE: Genuine leather has no grain marks and a satiny surface. Usually, it is pressed with an artificial texture to give it a grainy look, which is how it is recognized. Genuine leather is mostly used in low-quality products due to its low price and availability, such as shoe soles.
AGING OR PATINA: Genuine leather will not produce a patina of any kind. As the leather ages, it will result in surface cracking.
The infographic below summarizes the differences between the three main types of leather for your easy understanding.
How to Identify Leather types:
Not all of us have easy access to microscopes or even magnifying glasses, so we have to rely on more traditional methods of identifying leather.
Full-grain leather has a grainy surface due to hair follicle attachment. Also, the surface might have smaller cuts or bruises, which will further confirm your observation. If you cut the leather and look at the cross-section, you will see a dense layer near the top surface, and the density of the fiber decrease when you travel downward.
Top grain leather is essentially a full grain leather slightly buffed and sanded on top. You can still see grains, but compared to a full grain leather, its surface is smooth and free of imperfection.
Genuine leather is easy to identify. As it's obtained from the innermost part of the hide, the natural surface is satiny, and most manufacturers imprint them with artificial surface texture.
This texture is uniform across the surface and is easily identifiable. Genuine leather is the most abundant leather in the market, so ensure you don't confuse it with the high-quality full grain or top grain leather.
Leather selection for any specific product or application is an essential part of the overall product design. The nature of the product and its intended use dictates which leather is suitable for it.
There is no one-size-fits-all formula for leather selection, and it boils down to the personal experience and industry learning of the design team.
For example, high-quality men's wallet is created from full grain leather, while top grain leather is more readily available and is used for garments, bags, and jackets. Genuine leather is also used but for lower quality commodity products.
Chrome tanned Buffalo leather is commonly used in products like shoes where they are prone to a substantial amount of wear and tear.
Leather fits the need; the need doesn't fit the leather.
You cannot use Chrome tanned leather for a knife sheath as the chemicals used to create the leather does not react well to metals.
We discussed a lot of topics in this short article, including leather types, how it is made, and how we can differentiate between various leather types.
Although to be truly expert in the identification of the suitable type of leather, you will need years of experience; this guide provides you with the most basic understanding of leather and its types.
I hope this will help you with you the next time you go out to buy some leather products or want to impress your friends with your knowledge of leather.
Until next time.
UPDATE: If you want to know about leather cleaning best practices in the wake of the ongoing Coronavirus pandemic, please check out our recent blog post on How to disinfect your wallet, keys, and phone, etc.