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What is vegetable tanned leather?

What does vegetable tanned leather mean, and what is leather tanning anyway?

First, let’s understand what leather tanning actually means. 

Leather tanning is the process of taking an animal hide and treating it to create leather.

Vegetable tanning utilizes natural tannins from trees, these tannins prevent the animal hide from decaying, preserving the hide to create leather.

Our vegetable tanned leather is made with natural tannins from quebracho & mimosa trees, which are both native to the Andes. Vegetable tanned leather can be made with tannins from other types of trees, such as chestnut  oak, or fir trees. 

The word tanning comes from the word tannin – which stems from the word tanna – an old Germanic word for an oak or fir tree. Thus, the meaning of the word tanning originates from the use of tannins in vegetable tanned leather.

There are two ways to tan leather: vegetable tanned leather, the original, natural way, and the cheaper, industrial way – chrome tanned leather. So what is chrome tanning, and what is the difference between vegetable tanned leather and chrome tanned leather?

Vegetable Tanned Leather vs. chrome Tanned Leather

Vegetable tanned leather is made using natural tannins from trees. Chrome tanned leather is tanned with chromium III and other toxic chemicals. We make our vegetable tanned leather using tannins from quebracho & mimosa trees. Making vegetable tanned leather takes longer, and costs more, than making chrome tanned leather. A batch of chrome tanned leather can be finished in hours, vegetable tanning is more of an art, taking weeks to finish.

Vegetable tanned leather hanging to dry after the natural tanning process is immediately recognizable as leather. After vegetable tanning, our leather is a beautiful beige color without any dye, we call it our “Natural” color. We then dye our Natural leather with aniline dyes to make our other three colors, Café (dark brown), Miel (Honey) & Noche (Black). Our leather is never painted, the color won’t peel or fade over time. In fact, our leather will develop a patina, meaning it naturally darkens and softens over time from sunlight, oxygen, and oils from your hands.

90% of leather in the world is chrome tanned leather. Even though chrome tanned leather dominates the global leather supply, if you saw chrome tanned leather after the tanning process, you’d never recognize it as leather. Chromium III is a blue powder, so when hides are tanned with chrome, they come out a pale blue. Chrome tanned leather is referred to in the industry as “wet blue.” Chrome tanning also kills the natural leather smell. Because of its unappealing color and chemical smell, wet blue needs to be heavily processed after tanning to make it usable. To trick consumers into thinking of chrome tanned leather as high-quality, companies actually spray it with an imitation leather scent. Chrome tanned leather is almost always painted to hide the blue hue. Paint can be scratched off with your fingernail, and will eventually peel and fade with time and use. Chrome tanned leather won’t develop a patina like our vegetable tanned leather.

The chemicals involved in chrome tanning are dangerous for the health of leatherworkers, and pollute the surrounding environment.
Our vegetable tanned leather is safe for the environment, leatherworkers, and you.

Read more about the effects of chrome tanning on the environment, and the health of leatherworkers.

What is Full Grain Leather?

 

Full grain leather is the strongest and longest lasting leather that exists. The grain is the outermost protective layer of the hide, giving leather its durability and longevity. Full grain leather leaves the hide untouched. 

Marks or scratches, like branding marks or bug bites, show up on the grain, the outermost surface. Leather starts with the hide, and hides are graded by how many marks are visible. Hides with tons of marks and scratches are graded lower, and cost significantly less, than hides with fewer blemishes. We start with the highest quality hides with just a few marks, so that we don’t have to compromise strength for beauty. Most companies sand down the grain to produce a blemish free surface, sacrificing the longevity and durability of the leather. Alta Andina celebrates the unique beauty of each hide by leaving the grain untouched, so that the leather’s strength remains uncompromised. Without the grain, leather is like Robin without Batman, lacking the strength to get the job done. 

Now that we know what full grain leather is, let’s walk through the structure of a cow hide.

There are three layers in a hide:

The Grain: The outermost protective layer of the hide, that connects to the hair of the animal. The natural fibers of the animal are tightly bound together, giving the leather all its strength and durability.

The Junction: This middle section is where the grain meets the corium, and the fibers start to weaken a bit, losing a lot of their tightness. 

The Corium: The under layer of the hide, where the fibers are loosest and softest, or just a fancy word for suede.

Full grain leather is defined by leaving the grain intact. Pretty simple, do less to the hide, and it will last longer, and develop a rich patina. With other types of leather, like top grain or genuine leather, the grain has been sanded down or completely removed to produce a blemish free surface. 

What is a Patina?

A patina is the natural darkening and softening of leather over time that occurs as a result of exposure to sunlight oxygen, and the natural oils in our skin. Think about your old baseball glove, stiff and uncomfortable before you worked it in. An old baseball glove is darker, and molded perfectly for your hand – that’s a patina. A good patina is one of the hallmarks of full grain, vegetable tanned leather.

What is top grain leather?

To make top grain leather, the grain is sanded down to produce a smooth, blemish free surface. 

Top grain leather is commonly used when companies buy cheaper hides to start. Remember that it all starts with the quality of the hide, higher quality hides have fewer marks, and cheaper hides have lots of scratches, branding marks, and blemishes. Top grain leather allows companies to buy cheaper hides, sand down the grain, and pass it off as higher quality leather.

What is corrected grain leather?

Corrected grain leather and top grain leather are similar. The difference lies in how much is actually done to the leather. Corrected grain leather goes one step further from top grain leather, and after being sanded down, it is stamped with an artificial pattern to give the appearance of a natural looking leather grain.

What is suede? 

Suede is one of the natural layers of leather (the corium) and can be used in all sorts of interesting ways. It provides that soft, luscious texture. Suede is the surface opposite the grain. Suede is often split from the rest of the hide to use for fashion and upholstery. Suede is not better nor worse than full grain leather, they have completely different applications.

What is bonded leather? What is genuine leather?

Bonded leather and genuine leather are used interchangeably these days. When leather hides are shaved down on the suede side to ensure the leather is the same thickness all the way through, little scraps of leather fall to the floor. Bonded leather is made with those leather scraps from the floor. Those scraps are mixed with chemicals, polymers and plastics, to produce “leather.” Bonded leather is shiny, and completely uniform, it looks like plastic. The term genuine leather is used to differentiate bonded leather, from polyurethane leather, as they look almost identical. Polyurethane leather or “pu leather” contains no actual leather, it is plastic.

We never use the term genuine leather – why not? 

Genuine leather is an immediate red flag. The term genuine leather is a misleading marketing term used to make bottom of the barrel leather sound high quality. As we know from above, genuine leather is the term used to describe bonded leather, and differentiate it from polyurethane leather. Leather scraps from the floor of the tannery are melted  down, mixed with some plastic, chemical junk to hold it together, and voilà! – you’ve got yourself some genuine leather. Saying genuine leather is real leather is kind of like claiming genuine fast food burgers are “100% real beef.”

Chrome tanned leather: environmental impact

Unfortunately, 90% of leather in the world is chrome tanned. During the industrial revolution, the leather industry moved away from vegetable tanned leather and turned to faster, cheaper, chemical alternatives, mostly chromium, for the tanning process. The globalization of the leather industry has pushed the environmental degradation, and human health risks out of sight and out of mind. Developing countries like Bangladesh and India bear the burden of chrome tanneries.

Beyond pushing the human problem of chrome tanned leather production out of sight, the leather industry works in developing countries because environmental regulations rarely exist, and are rarely enforced if they do exist. Therefore, leather tanneries can dispose of solid waste and wastewater without treating it first, making the tanning process significantly cheaper. Without proper treatment, “wastewater and solid waste from tanning operations often find their way into surface water, where toxins are carried downstream and contaminate water used for bathing, cooking, swimming and irrigation.” (1) The chemicals used in the tanning process thus make their way into soil which can make fields too toxic to grow food.

Hazaribagh, a neighborhood of Dhaka, the capital of Bangladesh, is a microcosm of the global problem with chrome tanned leather. It is estimated that every day, 5.8 million gallons of untreated wastewater makes its way into the Buriganga river, once the main water source for the capital cities’ 7 million people. (6)

Leather Tanning and Hexavalent Chromium

The European Union banned the use of chrome tanned leather in automobiles, which should spark concern as to why chrome tanned leather accounts for 90% of the world’s leather supply. The health risks of hexavalent chromium to the health of leatherworkers are frightening. 

Chromium has two forms with an important distinction. Trivalent chromium, or chromium III, is benign to humans at low levels, and can be found occurring naturally in soil, animals and plants. Hexavalent chromium, or chromium VI, is a proven carcinogen that causes cancer, respiratory problems, and damage to internal organs. 

While hexavalent chromium is not used in leather tanning, chromium III is the main ingredient in chrome tanning, and “under certain production and storage circumstances Chromium III can transform to Chromium VI.” (2) More specifically, “chromium VI compounds can be formed in leather through the oxidation of chromium III compounds.” (3) Thus, what begins as Chromium III can actually become Chromium VI through oxidation, i.e. normal production or storage practices. 

Leatherworkers have to physically get in vats of Chromium III to retrieve hides, and are subjected to working conditions where they are barefoot, without gloves, masks and other protective equipment. These leatherworkers have been found to have cancer, serious respiratory problems, and permanent skin rashes and discolorations. 

The skin irritations from chrome tanned leather can go beyond the leatherworker, all the way to you – the user of the chrome tanned leather product. Between 1 and 3% of the adult population worldwide is allergic to chromium and will react to chrome tanned leather with serious skin irritation. Someone using a pair of chrome tanned leather gloves or sandals, for example, can develop rashes and sores. In fact, “in 2011, a small scale Danish study (8) found that almost half of imported leather shoes and sandals contained chromium VI.” (7)

Where does your leather come from? Do brands tell you? Unfortunately, leather coming from places like Hazaribagh makes its way into the global supply chain with a deafening silence and lack of transparency. Big brands hide behind leather buying associations, so that they can claim they do not know the original source of their leather. But big brands and leather buying associations have been caught and exposed, showing that their leather originates from places like Hazaribagh. If a company is not fully transparent about their supply chain, what are they hiding? 

At Alta Andina, we are proud to highlight our entire supply chain, including our leather supplier, Curtiembres Del Valle.

Vegetable Tanned Leather vs. Vegan Leather 

Vegetable tanned leather is not vegan leather. Our vegetable tanned leather is all high-quality cowhide leather, sourced from a single abattoir. Vegan leather is made from an alternative to cowhide, commonly polyurethane. However, vegan leather can also be plant based, recently exciting developments have been made in the areas of mycelium leather, and cactus leather. 

Mycelium leather is grown in a lab setting, producing the closest market alternative to high quality, vegetable tanned leather. Mycelium is the vegetative body of the fungus, a thread that branches out under soil, and can produce mushrooms. Because of the web or root like structure of mycelium, it ends up emulating the fibers of cowhide leather. By growing mycelium leather in a lab, many factors can be manipulated to create a specific texture or thickness. Thus, it has a more durable, rigid, and leather-like feel than other plant based or synthetic leathers. It is sustainable in every way imaginable. Other sustainable plant based vegan leathers are made from pineapple, and cactus.

Cactus leather is plant based leather, made from the cactus plant. It is free of any fossil fuel derivatives, or chemicals used to produce polyurethane leather. The cactus plant is a particularly sustainable crop, as it can be grown using only rainfall, without any additional irrigation Cactus leather has a soft, malleable texture, but can easily rip or tear as a result. While cactus leather lacks the strength and longevity of vegetable tanned leather, it is a great material for specific purposes, like as an alternative to polyurethane leather.

Polyurethane leather originates from fossil fuels. Oil is used to make materials like polyurethane, and in order to do so, chemicals are added to oil, in order to give synthetic materials their useful properties. Phthalates, for example, are used to give plastics their elasticity and strength. Phthalates are among the many chemicals used to produce polyurethane leather, and they have an alarming effect on human health. It only takes a quick search to see that we’re absorbing these chemicals from the plastics around us. Phthalates are endocrine disruptors. Endocrine disruptors are linked to different types of cancer, obesity, and may affect male fertility. That list does not even cover the entire scope of human health risks associated with endocrine disruptors. 

While polyurethane leather obviously has benefits we haven’t mentioned, we’re strongly opposed to the excessive and dangerous use of plastics, and fossil fuel derivatives. The dangers to the environment, and risks for human health, are well documented and intricately linked. 

Our vegetable tanned leather is safe for the environment, biodegradable, and free from the awful chemicals and fossil fuel derivatives used to make synthetic leather.