Vegetable Tanned Leather – Process and Benefits

Vegetable tanned leather

Vegetable tanning refers to leather that is tanned with fruit, roots, leaves, oak and spruce bark. Also quebracho, tara pods, olive leaves, rhubarb roots or mimosa are common. These substances are placed in a pit along with the skins and hides. As these tannins are derived from plants, the leather is called vegetable-tanned leather. Vegetable tanning is  taking more time than chrome tanning which can be done in a day, but far more worth it environmentally.

History of Vegetable Tanned Leather

Vegetable tanning is the oldest method of tanning, this tanning has existed for over 5,000 years. Some evident reveal that vegetable tanning was around in 4th millennium BC in Egypt. Several type of leather were prepared for various uses in Ötzi discovery in the ice of Alps. Recently, we found the more modern and industrialised tanning methods have become common and it can be assumed that nowadays only 10 – 12% of all leather is vegetable-tanned. Historically, each region or country has its own used available materials for tanning process, in Europe mostly used chestnut and in UK oak.

Is leather sustainable?

Big scale production of the leather using hash chemicals can give serious impacts to the environment, but the are more sustainable options. Tanning with vegetable materials and using the by-product of meat and dairy farming will reduce environmental impact significantly.

Tanning with chromium will give bad impact to the environment, furthermore with lack of waste treatment. Beside the use of chromium, amount of water required for tanning process also become 2^nd problem. Also, as it is a by-product of the meat and dairy industry you could argue that it is included in that environmental impact as well. By using hides as leather raw material, it will reduce the waste of these industry significantly. Our main leather supplier is Kasin Leather, finest Indonesian vegetable tanned tannery, Starting as a sole producer for the Japanese and Indonesian Army’s boots, it is one of the oldest leather tanneries in Indonesia, and until today is still the best sole leather producer in the country.

Nowadays, so many product created using vegan leather, but still give environmental impact as long as they use synthetic materials, like PVC, that derive from fossil fuel like petroleum. Also. Water waste and sometimes toxic dyes are additional environmental impactors of the faux leather industry. Some of vegan leather made using cork or pineapple leaves, but still require plastic based adhesives to hold fibres together.

Tannins

Every plant contains different percentage of tannin. During stressful reaction of the plant (e.g. parasite attack) will release mainly substance. Even same plant, will content tannin in varies:

1. Oak bark contains about 10% tannins (in older trees about 5%) and oak apples up to 70%. The resulting leather is light brown.
2. Chestnuts can reach 10 percent tannins in wood of old trees. The leather is medium brown and chewy.
3. Willow bark has 10% tannin and delivers yellowish leather.
4. Spruce bark has 15% tannins. However, in spruce wood it is a maximum of 1%. Also, this leather is light brown.
5. Valonea has a very high tannin level with 32%. The leather is tough and solid.
6. The bark of old birch contains 10% tannins. The resulting leather is also yellowish and soft, but resistant.
7. Galls or cecidia contains 55–65 % tannic acid. There are over-growths on plants through the eggs of insects. Around the larvae, tannin-containing growths develop. The countries of origin are Hungary, Yugoslavia and Austria.

Vegetable Tanning Process

• Pre-Tanning

Preparing the leather by rehydrating the hides and removing the hair in couple days.

• Tanning

Here’s a great video from pellevegetale that provides an overview of the process:

The tanning agent is placed together with the hides in water-filled pits, resulting in a bath containing tannic acid after a few days. The skin is regularly exposed to additional baths with higher tannin concentrations and must be frequently tended to in order to ensure full absorption. The hides are then removed, excess moisture is taken out and they are shaved to the desired thickness (from the backside).

For vegetable tanned leather that isn’t dyed, this is nearing the end of the process. That type of vegetable tanned leather has a pale almost pinkish color to it. While dyed vegetable tanned leather need further dyed process to get rich color and character.

• Dyeing, Hot Stuffing, Drying

Tanned hides ready to be infused with color, the hides are dyed in enormous drums and rotates. The leather may then be hot stuffed, which is a special process that literally stuffs the leather hide to its core with waxes and tallows that give it a rich color and make it more durable. And then, the hides are dried and staked. Staking is a process that softens up the leather just a bit.

• Finishing the Leather

The hides are sprayed with waxes and a sealant for protection. The entire process is very time and labor intensive, taking up to six weeks to complete entire the process, that’s why the price of vegetable tanned leather is higher than chrome tanned leather.

The light fastness of vegetable-tanned leather

Uncoloured vegetable tanned leather will darkens by light, moisture and fat, but the dyes in pigments or aniline leather become lighter by light.

Veg tan will become darker first that never oiled or moistened or greased, and brighter later as a result of drying. Apparently this effect is related to oils and fats in the leather. At first, grease moves up to the top of the leather and darkens, but the dryness makes it brighter with time because the fats slowly dry out. But as soon as water or grease gets onto the leather, it darkens strongly.

The Benefits of Vegetable Tanned Leather

All in all, the main benefits of vegetable tanned leather are:

• A longer life: Leather brief cases and handbags are often so long lasting and loved that they pass from generation to generation.
• That it is more eco-friendly than its siblings – Synthetic Faux Leather and Chrome Tanned Leather.
• The process is traditional and safer for those tanning the Leathers.
• A rich patina:Any vegetable tanned article that is in everyday use ages in a way that enhances its character and its beauty.

Find our best vegetable tanned leather product: backpack, wallet, messenger bag.