Vegetable Tanned vs. Chrome Tanned Leather

The process of tanning leather is quite fascinating. After the leather is split at the tannery, it undergoes tanning to remove perishable oils from the hides and preserve it for a long-lasting life. This process essentially transforms the animal hide into leather, making it suitable for various purposes. Tanning leather involves changing the protein structure of the raw hide into a stable material that won't decay.

There are two primary methods of tanning leather: vegetable and mineral. Over time, tanning methods have evolved, from ancient earthen vats to modern industrial machines. 

Determining the quality of leather based solely on appearance can be challenging. In essence, nearly any type of leather can undergo tanning and finishing processes to mimic the appearance of a different kind of leather. However, the true measure of of leather quality lies in its fibrous structure and its authenticity. There are a lot of choices that go into the tanning process to convert a raw skin into a material that's suitable for product manufacturing, and each decision is tailored toward the final result: which could be to make it inexpensively, quickly, or with high quality.

Vegetable-tanning (oak tanning, oak leather)
Vegetable-tanning, which uses naturally-occurring tannins found in plants, especially tree barks, remains one of the oldest and most reliable tanning methods still in use today. Although it was once widely practiced, it has now become a specialized technique.

Whether it's in the earthen pits that are still used in traditional tanning in places such as Northern Africa, or in modern tanning machines, the hide is immersed in a tannic solution of water, ground plant bark and leaves. The tanning solution typically contains oak, but it may also use other trees like hemlock, birch, or chestnut. Due to its natural materials, vegetable-tanned leather is highly regarded as the most eco-friendly tanning method. Moreover, it is incredibly rare, accounting for less than 10% of all leather production.

Genuine vegetable-tanning is a lengthy process, with a minimum of one month. The resulting leather is carveable, moldable, and structural. It is also natural and breathable, requiring minimal finishing. It ends up being a “one of a kind” leather.

Mineral-tanning (chrome-tanning, chrome/mercury)
Mineral-tanning, also known as chrome-tanning, is a modern method of tanning developed in the late 1800s for industrial mass-production. Mineral salts (chemicals and metals) like chromium and mercury are used in the tanning process instead of plant tannins, and shelf-stable oils are added for suppleness and flexibility.

90% of leather is chrome-tanned nowadays, and that is partly due to the fact that the mineral-tanning process is much faster - it can take just one day to complete. The leather is soft and drapes like fabric, and can be dyed in any color as its natural hue is bleached out during the wet blues process. So, chrome-tanned leather is the preferred leather of the shoe and fashion industries. This leather type is commonly used for jackets, gloves, and upholstery for car seats. Because of its quick processing time, it is less expensive than vegetable-tanned leather.

Conclusion
To sum up, the main difference between these two types of tanning is that vegetable tanning uses natural agents while chrome tanning uses chemical agents. Chrome tanning is much faster than vegetable tanning, which makes it less expensive, although vegetable tanned leather is associated with heritage and natural craftsmanship. Leather Unlimited offers a variety of leathers from both types of tanning, all carefully selected to have excellent quality for different leathercraft projects.