Vegetable Tanned Leather Vs Oil Tanned Vs Chrome Tanned - What's The Difference?
Wondering what the difference is between vegetable tanned leather, oil tanned leather and chrome tanned?
Which should I get? Does it even matter?
All great questions.
Tanning is the process of preserving leather, which is the skin of an animal. The tanning process essentially stops the process of decomposition by giving the skin a chemical bath. This process modifies the proteins in the leather and stops decomposition in its tracks.
What makes the difference, of course, is the kind of chemicals that are used. There are a number of different tanning processes but the most common you'll find are vegetable-tanned, oil-tanned and chrome-tanned. There are also some hybrid methods, which we'll talk about.
So, let's run down the differences and why they may or may not matter.
Vegetable Tanned Leather: Made With Plant-Sourced Tannins
"Tanning" is called that because leather is preserved by subjecting it to a chemical bath rich in tannic acids; vegetable tanned leather is so named because the tannins come from plant sources.
Yes, tannins, the same compound that makes wine taste "dry." Some people say such wines have too much oak...which is actually the case.
You see, the Latin name for oak trees is tannum. Tanning, tannins and tannic acid are so named because they are sourced from oak bark, which - to this day - is one of the most common sources of tannins used for tanning leather.
There are other plant sources, of course, but oak bark is still the most common.
Vegetable tanned leather, therefore, is made using plant-sourced tannins.
Why does that matter?
Vegetable tanned leathers, such as English bridle leather, tends to produce stiffer leather when the tanning process is complete, as well as a more uniform coloring when died.
Okay, so what does this mean when it comes to, say, vegetable tanned leather boots?
Vegetable tanned leathers tend to require more break-in, as they are a little less pliable than other leathers but also more durable.
They take polish very well and also respond very well to applying conditioners and greases for waterproofing and preservation. If shining is a top priority, they do take a shine very well but aren't always as easy to get to the high mirror shine as other kinds.
Vegetable-tanned leather also develops patina over time, which many people find highly desirable in quality leather items.
These leathers are very well-suited to working applications, such as work boots, belts, gun holsters, and horse tack, but also work very well as dress boots and shoes given the smooth, even finish that quality leathers have.
Oil-tanned leather is something of a misnomer, as oil tanned leather isn't tanned by an oil as opposed to a chemical bath, but rather impregnated with certain oils as part of the tanning and dyeing process.
Oiling is actually part of the post-tanning process; it isn't actually part of tanning itself. However, this treatment of the leather does change the material to give it some qualities which some find desirable.
Impregnating the leather with oil gives it a bit more hydrating, essentially sealing the molecules of the hide with a layer of lipids (fats) and coating them.
This has the effect of partially waterproofing the leather (to a degree, more in a second!) as well as making it softer, more pliable.
The upshot is that you have leather that's easier to waterproof as well as being softer. This minimizes break-in time. A number of boot companies on the market use oil-tanned leather in making boots that are known for needing very little break-in before the boots are comfy.
Oil-tanned leather drinks up waterproofing such as neatsfoot oil and boot grease, requiring far more of it to stay waterproof than vegetable-tanned leather.
You'll notice the dye shears with pressure. Squeeze a bit of oil-tanned leather in your fingers and you'll notice it lightens as the oil particles run away from the pressure and that is how the patina will develop.
You also have to be very careful with boot treatment, as the leather will darken asymmetrically. If appearance is a priority, meaning they aren't work boots, this may be highly undesirable. Granted, if your boots are black it's not such a big deal, but definitely is if they aren't!
They take polish just fine, and can be shined up pretty well. However, the natural appearance is rather muted. With polishing, they can shine, but it will be more of a matte than glossy.
Oil-tanned leathers are fine for working applications, as it's common for some work boots or work gloves, though without the rigidity of vegetable tanned leather.
Chrome Tanned Leather
Chrome tanned leather is treated to a manmade chemical bath, particularly one rich in chromium sulfate. The solution has the same effect as vegetable tannins in terms of the effect in preservation, though the final product will differ.
The use of chrome tanning arose during the Industrial Revolution, and has largely supplanted vegetable tanning as the dominant method of producing leather given that synthetic compounds that can be made on an industrial scale are easier to procure in quantity than organic ones.
However, some tanneries are known to use a hybrid process, combining chrome and vegetable tanning in a two-stage process. This includes Chicago's Horween tannery, as this is the process that produces Chromexcel leather.
What is the upside of chrome-tanned leather?
The upside is that chrome-tanned leathers tend to be more pliable and softer than vegetable-tanned leather, making them softer and reducing the break-in period. For those wanting to, chrome-tanned leather also takes a high-mirror shine like nobody's business.
However, just as with oil-tanned leather, you have to be careful when it comes to treating it for preservation as asymmetrical darkening can occur when applying grease or oil. Chrome tanned leather responds very well to dubbin, a wax-based leather preservative compound.
Chrome-tanned leather also tends to maintain a more uniform appearance over time, without developing the patina that vegetable tanned leather is known for.
It's more supple than vegetable tanned leather, but also doesn't have the same stiffness, making it a little less suited to working applications requiring the utmost of support. It's great for light duty, but not necessarily for hard-working professions.
What Is The Best Leather For Work Boots?
Ultimately, it's not so much that any one is better than any other, it's more that leather made with each of these tannings methods have certain attributes that leather made with other tanning methods may not.
Quality leather is quality leather, and a great pair of boots will always be a great pair of boots.