Leather Basics – The Good, the Bad and the Ugly
Leatherworking is one of the world’s oldest crafts. Ever since humans could use tools and hunt they have been using leather to make a huge range of goods; clothes, jewellery, tools and armour. Although there have been many new processes and uses for leather some of the older production methods and techniques remain by far the best in terms of quality, durability and attractiveness.
Some of those newer processes have made the world of leather a confusing place for consumers, and it has become increasingly difficult for the layperson to ensure that they are getting quality leather goods. Often this means wading through the marketing and learning some of the common terminology when it comes to different types of leather.
Leather can be made from the skin of many animals, but by far the most commonly used is cowhide. Most cowhide is produced as a by-product of the meat industry, and accounts for approximately 5% of the value of a farmed cow. The hide itself has very few uses, and if not made into leather would (in the vast majority of cases) be discarded.
At Titan Leathercraft we use cowhide in all of our projects. We do from time to time use other leathers, most often as lining (i.e. pig suede or rabbit fur) or as feature panels or inlays (i.e. deerskin, snakeskin etc.). The majority of our leather is British in origin, sourced from Northampton. On occasion we also sometimes source some additional leathers from Spain if we can’t locate available supplies in the UK.
In order for a hide to usable it must first be put through a tanning process. This is a process that has been in use in one form or another for thousands of years.
There are several stages to the tanning process:
- Curing, usually with salt: Curing arrests the decaying process and prevents bacterial growth.
- Soaking: Soaking removes excess salt from the curing process and increases the moisture level ready for subsequent steps
- Liming: This treatment assists in removing the hair from the hide, as well as removing the natural grease and fats to some extent
- Scudding:Remaining hair is removed from the hide, initially with a machine and then by hand using a dull knife
- Deliming and Pickling:This removes any of the remaining agents from the hide
- Tanning: Leather is tanned in one of two ways; chromium tanning and vegetable tanning
Approximately 90% of the world’s leather production is tanned by soaking the leather in a solution containing metal chromium. Chrome tanning is widely used as it is can be anything up to ten times faster than the alternative method. Chrome tanned leather has a blueish appearance in its finished state, but dyes are usually added as part of the tanning process. On the downside chrome tanning changes the texture of the leather to some degree, and the chemicals used are harmful to the environment (and those chemicals can cause adverse reactions for some people)
Vegetable tanning uses tannins which occur naturally in the bark and leaves of many plants. Tannins bind to the collagen in the hide and coat them. Hides are stretched on frames and immersed for several weeks in vats of increasing concentration of tannin.
Vegetable tanned leathers are not uniform in appearance, each piece of leather becomes a unique item in itself, possessing its own rich shade. Vegetable tanned leather is extremely strong and takes natural dyes very well. This form of leather is also far better than chrome tanned for moulding and carving designs.
At Titan Leathercraft we use vegetable tanned cowhide in all of our projects. Most of our hide is tanned using Oak leaf tannins
Types of Leather
To understand the types of leathers it is important to understand the constituent parts of the hide itself.
Cowhide is made of two main integrated layers – the corium and the grain. Collagen fibres in the corium are thinner and more flexible, and become tighter and thicker as they move up toward the grain, where the fibres are tightly packed and very sturdy. The corium becomes thicker with age, which is why calfskins are thinner, smoother and softer than the hides of older animals.
Commonly Used Leathers
Full-grain leather takes the entire grain of hide, with all the imperfections and inherent toughness of the material. It includes the epidermis, the grain and the corium junction.
Full-grain is hard-as-nails leather that will soften and develop a rich patina as it ages, looking more and more beautiful as you use it. It's widely recognized as the best and highest-quality leather money can buy. This type of leather is naturally marked with imperfections from the animal, like a brand or a scar, and higher priced items will have used carefully hand selected hides that are free of these natural marks.
Often much more expensive, full-grain pays dividends with its durability. If you invest in an item made with full-grain leather, you will probably have that item for the rest of your life.
At Titan Leathercraft we only use full-grain hide as the main constituent in all of our projects. We may use other grades of leather in parts of the project where appropriate (such as using suede as a lining leather).
Top-grain leather is the grade of leather you'll find in goods often labelled as "fine leather” goods and is the middle-of-the-road quality of leather. It's used in the vast majority of purses, wallets and some bags.
It's made by skimming a piece of full-grain leather and sanding away any imperfections in the hide and stamping a fake grain on it. Usually, it's then treated and coloured to provide a completely uniform look. It often won’t age as well as full-grain hide, but is still a sturdy and durable leather.
Split leather is the lower quality leather and is used in a wide variety of ways. Split leathers are formed from the bottom part of the leather, the part that is split off from the grain at the grain/corium junction. Split leather can then be sliced down even thinner and used for a variety of other purposes.
Often a polymer coating is applied and embossed to mimic a grain leather and a common use for this is in the production of “fake” ostrich or crocodile leather. Another common use is to split it into increasingly thinner layers onto which a vinyl or plastic coating is applied. This type of leather is commonly used in cheaper leather furniture and clothing.
Another use for split leather is suede, which has been textured to have a napped finish and its softness and pliability make it useful for a wide range of applications.
Bonded “Genuine” Leather
Bonded leather is the lowest grade of leather, because it is not really leather as most people would understand it. Bonded leather is constructed from scraps of corium, and years ago would have been discarded as waste material being of such low quality to be unusable. Now these scraps are shredded and ground together with glue to form a kind of mulch. This is then dried and often backed with an embossed polyurethane coating to give the appearance of higher quality leather.
It can be very misleading, but when you see a leather product that seems to be offered at an unbelievably cheap price it will usually be “bonded” leather. It will also often have a label proudly declaring it to be “Genuine Leather” or “Real Leather”. Well, it does CONTAIN leather, but it has none of the enduring quality of full grain or top grain leather, and will usually fall apart quickly.
One of the most common uses for bonded leather is in the construction of belts. If you see “genuine” leather belts being offered at “2 for £10” or similar then it is highly likely they are bonded leather. They might initially look similar to a hide belt, but use them for a few weeks and you will start to see the splits in the reconstituted material and it will often fall apart completely.