Vegetable tanned or chrome tanned?
It is one of the questions we can ask ourselves when choosing a skin, and one of the most difficult to answer. Many factors depend on the final choice.
Today you hear a lot about vegetable tanning, its quality, duration, respect for the environment, but... is it really like that? If this tanning process is so good, why do they continue to manufacture leather with chrome tanning? Read on to find all the answers.
Let's start at the beginning, the leather tanning process.
1. Supply of raw skins
Although vegetable tanned leathers and chrome tanned leathers are different things, the beginning of the tanning process is the same. It all starts with raw hides which are a by-product of the meat industry, so no animal is killed just to get their skins to make leather from. For example, let's look at calfskin. It is obtained from calves for meat and once skinned and fleshed we are left with the raw skin that still has hair.
2. Hair removal
In a tannery, the first step is to remove the hair and for this they are immersed in a chemical solution for about 24 hours. Although hair is removed today with a razor, in the past it was usually done with a dull knife or a special metal tool, but it can even be done by hand. Of course, the machines are much faster and more efficient, so they not only remove hair better and faster, but also any remaining meat or fat that may remain on the skin. While many tanneries simply discard the hair, others use it as biofuel, so they don't really waste anything in the process.
3. Rinse
The next step, a lime solution is sprayed onto those raw hides and they are then placed in wooden barrels where they are regularly rotated over the course of a day or two. During this rinsing process, the PH of the hides or skins is lowered so that they remain in perfect condition for subsequent tanning.
Once the skin is at the correct PH they come out of the barrels and now have this unnatural light blue color due to the lime solution. The jagged ends are cut off and with cutting machines, the leather is brought to a uniform thickness. Up to this point, vegetable and chrome tanned leather go through the exact same process.
vegetable tanning
Not all vegetable-tanned leathers are the same and, of course, depending on the use that is going to be given, the leather will be tanned with some tannins or others. For example, for shoe sole leather, oak bark tannins are often used. Others use chestnut tannins or the chestnut or mimosa fruits themselves. Sometimes tannins are also derived from the leaves. Each tannery uses its own techniques or tannin blends.
Tannins usually when used in a tannery, arrive as a powder which is then mixed with water to create a liquid solution. The prepared hides are then completely immersed in this water and tannin bath. Most tanneries have different wells with tanning solutions of a different concentration and a hide may start at the lowest concentration and work its way up to the highest concentration, thus giving a superior product. This entire process can take up to 15 months. Once this process is complete it is time to color them.
4. Smoothing and treatment
After tanning, the hides are quite stiff and hard, so they can also be softened. Coloring and softening can be done at the same time in drums; they may be metal drums, but traditionally they used to be wooden drums. Depending on the desired finish, items such as fats or waxes such as beef tallow or beeswax can now be added and, although they are harsh under room temperature conditions, heat can be applied to ensure that it is evenly coated on the top surface of the final layer.
Once again, each tannery has its secret recipes and procedures that are not publicly known. This is why hides from different tanneries may seem similar at first, but once you get up close, once you touch them, once you feel and smell them, you can always tell that there are subtle differences between the hides.
Leather is typically tanned, treated, and finished with a specific purpose in mind. Therefore, the leather of a shoe upper has to be different from the leather of the sole of the shoe and the leather of a glove or the leather you want to use for a bag or small leather goods. Because? Well, just think of a glove made of stiff leather. Not only is it uncomfortable, it also doesn't fit well and you want some flexibility so your hand can move comfortably. At the same time, if you use this leather on the soles of your shoes, it will wear out in a few weeks.
5. Wash and finish
Once the leather is colored and to the appropriate softness, it is washed and then de-moisturized, typically by machine or air-dried under very specific conditions of temperature and humidity levels. Last but not least, the leather finishing process can have a huge impact on how it is perceived and sometimes a lesser quality leather at this stage can finish very well and look good because it has been given a good leather finish.
There are differences in whether the leather is dyed by hand or by machine. It can also be finished by spraying, embossing, rubbing or sanding. You can also polish it, roll it, polish it, or have a combination thereof.
On our website you will find high-quality vegetable-tanned cowhide skins ready to be used in any of your jobs. You can see them at this link, https://latendetadelcuero.com/collections/vaquetilla or by clicking on the following image.
Tannins can also be found in urine, so there are traditional ways to care for leather using urine. Yes, you heard right: pee! I even know people who went to Morocco and bought a very nice leather bag. When they got home they realized that there was a very strong smell in their room. It was the leather bag and in the end they had to throw it away because there was no way to get rid of the smell.
In recent years, vegetable tanning has become increasingly popular, and you can find vegetable-tanned leather on virtually every continent, except perhaps Antarctica. There are hundreds of tanneries that produce beautiful leathers. These vegetable-tanned leathers take a long time to be tanned and colored, and because they are typically not pigment-dyed or top-coated, it means that vegetable-tanned leathers are higher-quality leathers, and that, Of course, it translates into a higher cost than conventionally chrome-tanned leathers.
chrome tanning
When it comes to chrome tanning, the main reason people use chrome salts is because it speeds up the tanning process and tanned leather can be obtained in less than a day. On the one hand, large chrome-tanned leather factories can be almost completely automated from start to finish, but they can also be made in a very traditional craft style, such as vegetable-tanned leather. Probably 90% or more of today's leathers are chrome tanned.
Again, although many enthusiasts claim that vegetable tanned leather is always superior to chrome leather, it is a fact that there are excellent chrome tanners out there that provide amazing quality leathers and people love their products. Also, high-end brands use chrome-tanned leather and really focus a lot on quality. So, to say that the leather is better or of higher quality because it is vegetable tanned, is simply not true.
Advantages and disadvantages between chrome and vegetable
1. Smoothness
Chrome tanning allows you to finish leathers that are really thin, soft and flexible, which is perfect for the production of gloves, textiles...
2. Water resistance
Chrome tanning is slightly more water repellent than vegetable tanned leather. That being said, you can treat the leathers with fluorocarbons or waterproofers that make the water slide off immediately protecting the leather. Of course, you can also get a repellent spray for fur and leather, but it's usually not as effective as when it's part of the dyeing and tanning process.
3. Color fastness
Chrome leather also tends to hold color much better and can also have a much wider range of colors and brighter compared to vegetable tanned leathers which are often a bit more subdued which can also be nice and stylish .
4. Heat resistance
Chromed leather also holds up better to heat, which is one reason why burnishing, which is a process that uses wax and heat to seal the edges, is so much easier on vegetable-tanned leather.
5. Absorbency and patina
Because most vegetable-tanned leathers are dyed with aniline or semi-aniline, they have a nice open-pore structure that is absorbent, so any sweat, grease, or wax you expose the leather to during regular use helps develop a unique patina. On the other hand, chrome-tanned leathers, especially those that are pigment-dyed, will not develop the same type of patina, but you can have aniline-dyed chrome-tanned leather that will also develop a beautiful patina over time.
Simply put, chrome tanned leathers allow for soft, supple and durable leathers that can be kept in a wide range of colors and on the other hand, a vegetable tanned leather is often duller in color but has a nice softness and soft to the touch and can be polished beautifully and develops a beautiful patina.
What are chrome and vegetable tanned leathers better for?
While some people swear by one or the other, we believe there is room for both depending on the use case. For example, the lining of a shoe should preferably be vegetable tanned because it is much closer to the skin. Also, if you are allergic to chrome, chrome leather is of course out of the question. Do you want your wallet to look good three years later? You probably want chrome-tanned leather. On the other hand, if you want to have folded edges and really darken over time and get this patina that tells a story, then vegetable tanned leather is better.
In terms of the environment, vegetable tanned leather is definitely better because the tannins are natural materials compared to chrome tanning which requires those chrome soles which are not easy for the environment to recycle. It also requires a lot of water to wash everything that in many parts of the world is a rare commodity.
How can you differentiate them?
Well, frankly just looking at it and touching it, it can be quite difficult. Even families of tanners who have been doing this for generations couldn't always tell if it was chrome or vegetable tanned. The best way to find out what it is, obviously, is to send it to a lab, but that's often impractical and very expensive, so the quickest and most decisive option is to burn the leather. If you burn a vegetable tanned leather, when the flame goes out it has a kind of white smoke, the flame is very orange and it doesn't have a particularly strong odor.
On the other hand, if you burn a chrome-tanned leather, it usually has a more bluish smoke and really smells strong and unpleasant. So when it has that smell, it's probably a chrome tanned leather. Of course, this is not useful if you have a finished leather product, so don't burn your shoe or bag!!
Purchase of chrome and vegetable tanned leather
If you still haven't decided whether you should buy vegetable-tanned leather or chrome-tanned leather, I have good news for you. Just buy the best of both. At La Tendeta del Cuero we have a wide catalog of leathers in both chrome tanning and vegetable tanning. You can see it by clicking on the following link See catalog
Conclusion Which is better, chrome or vegetable tanned?
Once again, there is no better or worse option. There is only the desired purpose and personal preference, such as if you have any allergies to chromium. What is much more important is how the leather is tanned, if the leather is of high quality.
We hope you find this article useful and help you understand a little about this complex world of leather.
Greetings and until next time!!