Leather is a multi-billion-dollar industry that has been around for thousands of years. From Roman and Medieval armour to leather jackets, Gucci handbags and wallets, leather is durable, beautiful and has a longevity that no other material can match. What makes it so amazing and more importantly what are the leather properties that make it so unique?
Leather is made up of collagen fibres, elastin, fats, water, sweat glands and erector pili muscles. The quantities and arrangement of these fibres and glands has a direct influence on its properties which affect strength, thickness, texture, stretch, permeability and water resistance.
Leather properties or genetic make-up are what make it unique, and looking at these in detail we can begin to understand how these influence its strength, stretch, permeability and lifespan. Let’s look specifically at full grain leather. Full grain leather undergoes the least amount of modification after tanning and is therefore more suitable to analyse.
Leather is a natural product that is biodegradable and sustainable.
The big advantage of leather is that it is natural. It’s also biodegradable, although Veg tanned leather can take somewhere between 25-40 years to biodegrade. Chromium tanned leather on the other hand can take hundreds of years to degrade as they contain more harmful chemicals that struggle to break down in the environment ie. chromium.
Leather is also a renewable resource and therefore sustainable. Cow hide or bovine leather is the most common type of leather available. Some species such as ostrich and kangaroo are considered exotic leather and have carefully controlled populations. A small quota are culled annually and a permit is needed to hunt them. If quotas are carefully controlled the supply of leather can be carefully maintained. I must just add that kangaroos are not specifically culled for their leather but rather their meat.
Wide variety of leather types.
There are many types of leather from cow to goat, lamb, kangaroo, horse, snake and alligator and much more. Each has unique properties, colour, type and strength. Some leathers are naturally thicker than others or have different textures. Think of alligator leather compared to cowhide? Or lambskin vs buffalo leather? They vary greatly in texture, thickness, softness and stretch all because of their genetic makeup and leather properties.
Strength of leather.
Full grain leather has incredibly high tensile strength and is the strongest type of leather. Only canvas, which is a man-made material, is stronger. The 4 grades of leather reduce in strength as layers are removed and the thickness is reduced. Full grain remains as is after tanning and there is no reduction.
Factors which contribute to leathers strength – How much collagen and elastin they contain and how these are distributed throughout the hide. Cow hide has the majority of elastin near the upper surface and gradually lessens the deeper you go. Whereas Kangaroo contains an even distribution of elastin throughout the thickness of the hide. This contributes to kangaroos overall strength and this is why it is the strongest leather for its thickness.
The arrangement of collagen fibres can have an influence on its strength. Or how much moisture is inside the leather as this prevents it from cracking and tearing. Please have a look at my previous post on what is the strongest leather for more info.
Good heat Insulation & Wind resistance.
Leather is impermeable to wind and that’s why it’s great to use for jackets, pants, skirts. The fibres are so closely arranged to each other that it creates an impermeable barrier that traps warm air internally but keeps cold air out. Leather is also semi-waterproof in that it will keep most of the rain out.
Resistance to abrasions and tearing.
Due to its genetic make-up of elastin and collagen fibres it is more resistant to scratches and abrasions. The thickness of the hide helps prevent tearing. The thicker the better. In some hides elastin is more prevalent at the surface and dissipates deeper into the hide. Kangaroo is an exception as it is a very thin leather with high resistance to abrasions as it has a high elastin content. It’s often used in motor racing suits because of its high abrasion characteristics and leather properties.
Some leathers are more resistant to tearing than others. Full grain leather, being the strongest grade, provides the most resistance to tearing. The hide is fully intact as no layers have been removed. Its original thickness isn’t altered. Thickness plays a big role but also the distribution of elastin.
Another factor is the arrangement of fibres in the leather. If the fibres are arranged in a cross-weave pattern or are they mostly parallel to each other? Fibres that are arranged parallel to each other are much stronger because less fibres are cut. Cross weave will result in more cuts to fibres. But at the same time cross weave in a full grain leather aides in its strength.
Stretchability and suppleness.
Leather can be stretched if needed. Most commonly shoes or boots need to be stretched if they are too small and there are different methods one can use to stretch it. For some more info see my post on the various ways to stretch leather. Certain leathers can stretch more than others.
Permeable to water and water resistant
Leather can absorb and release water and is water resistant to a certain degree. Leather can also absorb water and slowly release it when the temperature rises or becomes warmer.
Smell of leather.
The smell of leather almost reminds me of the smell of coffee in a way. It has a rich rewarding aroma which reminds me of craftmanship, quality and dedication to a craft that’s been around for thousands of years. You can almost smell the history in every hide. Every time I get a whiff of leather i am taken back to a time when life moved slowly and was much simpler…………………..maybe it’s just me, but that’s how I feel about leather.
Aesthetics and surface pattern.
There is such a wide variety and so many different types of leather, each has its own distinct colour, texture, feel and softness. Some leathers are more suited to be used for making jackets, others for handbags, furniture or boots. Check out this link to Tandy leather for some amazing leather you can buy.
Flame Retardant and non combustible.
Yes, full grain leather is non-combustible. Check out my post is leather flammable. Leather will smoulder when put over a flame but will not catch fire. PU leather on the other hand will burn quite easily when held over a flame.
Leather’s combustibility depends largely on how the hide was tanned and what chemicals it was exposed to during the tanning process. For example, the automotive industry requires a level of fire resistance in order to comply with fire safety regulations. The tanning process for this type of leather will undergo a different tanning process where fire retardant chemicals are added. Whereas handbags will not undergo the same process.
Lifespan of leather.
Leather properties allow it to last anywhere from 10 years to 50 years if cared for properly. In fact, it will outlast most fabrics by a long stretch if cleaned and conditioned regularly. I should also note that it’s best to keep it out of direct sunlight as that will dry it out. With time and if cared for properly leather will patina nicely and age beautifully. If you would like to know a bit more about the lifespan of leather check out my post on how long leather lasts.
Conclusion
The reason leather has been around for thousands is because it is a truly remarkable material and it has all the properties to back this up. Where else could you get a product that is bio-degradable, strong, wind resistant, stretchable, lasts forever, smells good, resistant to tearing and gets more beautiful as it ages. Mother nature is a truly remarkable engineer.
Thanks for reading and check out some of my other posts on my home page if you would like to learn a bit more about leather and leathercraft.