Leather is an organic material, which means that each piece your buy is unique. Add to that, leathers come from a variety of different animals. And then add to that, each tannery creates their leather using unique process and usually sells multiple brands of leather each made with their own process. All this variety is a great thing for the leatherworker, but can be overwhelming if you don’t understand the variables and what situations they are needed for. So...
Let’s Talk Variables.
Vegetable Tanned vs. Chrome Tanned
There’s a lot that goes into each of these tanning processes. What’s important to know is that one uses vegetal oils (from tree bark) to tan and another uses chemicals (chromium) to tan it. Vegetal tanned leather, generally referred to as veg tan, takes a longer amount of time to create, is considered higher quality, and therefore costs more. Chrome tanned leather has a quicker turn around time and therefore costs less.
The end product of these two processes are drastically different. Veg tan is generally thicker, more firm, and more durable. It’s the kind of leather you see in a nice pair of leather shoes. Chrome tanned is thin, very stretchy, and less durable. It’s the kind of leather that you see in a car that has a leather interior.
Each has it’s uses, but all guides and products on this website used veg tanned leather.
Cows vs. Other Mammals
There are a number of different animal leathers that are available to the leatherworker. Each have their own properties and different uses. Cow leather is the most available and works with most projects. As you’re getting started stick to cow leather to have a consistent medium for your work.
Thick vs. Thin
The first thing to know is the thickness of leather is generally measured in weight (oz) instead of thickness (mm). This will probably be a little confusing, but while you get used to it you can refer to this guide to translate. Each project requires a different thickness of leather. For example you wouldn’t want to use 10oz leather for a watch strap because it would be disproportionately large and probably not fit through the slot on the watch. You also wouldn’t want to use 3oz leather on a belt - it would be mangled in a day. As you are trying to decide what kind of leather keep in mind that generally the thicker the leather then less pliable the leather will be, but there are other factors that play into this. All in all, this is more of an art than a science, but you will definitely get a feel for it. If you’re having a hard time deciding, just let me know.
Supple vs. Rigid
As mentioned above, this is, in part, dictated by the thickness of the leather. However, the tanning process and the location of the cut also play into this. Some companies tumble their leather in a drum during the tanning process. A lot of tumbling means that the leather will come out pretty supple. Whether leather is supple or rigid is hard to gauge just by reading a description, and yet it’s a really important decision. You wouldn’t want to make a backpack out of rigid leather because it would be extremely uncomfortable. And you wouldn’t want to make a belt out of supple leather because it would lose its form. The best way to gauge this is by going in and seeing the leather for yourself.
Back vs. Belly
Animal skin is taught in some places and very loose in others. For instance the leather around the shoulders of a cow is thick, durable, has a tighter grain, and does not stretch much. The leather from the belly of a cow is not as thick, has a looser grain, and will stretch over time. The bend (behind the shoulders and not the belly) is somewhere in the middle. The cut of leather you buy also plays into how supple or rigid it will be.
Selecting the right leather is more of an art than a science
As you continue doing leatherwork you will get a better grasp on what you want for your project. I really suggest going in to see the leather if you can. If not, most tanneries have scrap laying around from the leather they are selling. They are usually happy to send you samples of the leather if you ask.