You might have heard people talk about vegetable tanned leather, or the tanning process in general, and wondered what it means and what the difference. Tanning is the process that converts animal hides or skins into leather. More specifically, it’s the process of using tannins (or tanning agents) to help preserve an animal’s skin, most often a by-product of the meat industry, in order to keep the collagen intact and stop proteins breaking down. This ancient process is required for all leather that eventually turns into leather goods, but not all tanning processes are the same. It’s worth understanding more about these differences as they can impact the quality of the leather, how sustainable it is and how long it will last for.
TANNINSTannins are organic compounds that occur naturally in plants - you’ll find them in bark, wood, leaves, berries and fruit skins. They act as a deterrent from pests or animals in the wild. There’s also an astringency to them; it’s what causes that slight dryness in a glass of red wine, and it’s why they work really well as a natural binding property for hides and skins to be turned into leather. Vegetable tannins are used to make vegetable tanned leather. The other main method, chrome-tanning, uses synthetic tannins. There are pros and cons to each, but it really depends on the type of product you’re making and its purpose.
Vegetable-tanned leather is usually a more time-intensive method which is why less than 10% of leather is made this way globally. It’s a practice that dates back thousands of years, and one that requires greater patience. The word tannin comes from the Latin “tannum” meaning oak bark, which is a clue to vegetable tanning being the original method of making leather. With this method, the hides are soaked in a vegetable tannin “liquor” and left for a long period of time – ranging from days to a year. There are now very few tanneries that have the desire or capability to produce leather in this way.
There are various benefits to vegetable tanned leather and one of these is the look, feel and smell. Many vegetable tannins impart a beautiful aroma that remains with the leather and, over time, vegetable tanned leather tends to take on a distinctive patina - darkening as it ages and from its specific use. Vegetable tanning is also a more natural process, which makes it easier for the tannery to treat its wastewater and reduce the environmental impact. It’s a process designed to celebrate the unique aspects between leather products, rather than chasing uniformity. This makes it an ideal choice for more personal items such as bags, wallets and shoes.
In comparison, chrome-tanning is a more efficient, industrial process and uses inorganic metal salts (chromium) as a binder, rather than plant extracts. Using this method you can process hide to leather in the space of a day, bringing the costs down significantly.
These chemicals tend to override the natural characteristics of the leather but as a result, chrome-tanning creates a more consistent product for industrial use. The colour tends not to change over time, it’s cheaper to both produce and buy, and that means it’s often easier to source than vegetable-tanned leather. It also results in a softer, more pliable leather than veg-tan so can be advantageous depending on what it’s being used for.
Typically you’ll see chrome-tanned leather used for furniture and car interiors. That said, chrome tanning requires more careful environmental controls. If you choose chrome, pay attention to the tannery and the country of origin as regulations vary hugely - there are horror stories of unsustainable methods used in its production.
BILLY TANNERY LEATHER GOODS
At Billy Tannery we combine traditional vegetable tanning with modern leather technology and make use of a meat by-product that would otherwise go to waste. Not only does our full-grain goatskin leather develop a beautiful rich patina with age - which means that every Billy Tannery product contains a unique point of difference - but we’re focused on a sustainable practice from start to finish.
Our farm-based micro-tannery in the British Midlands means that everything is sourced and produced in the UK to help reduce our carbon footprint. We’ve also worked with a local leather-expert to develop a uniquely sustainable tanning process, which means we’re able to recycle 90% of the water we use. We use mimosa bark extracts which are easily grown, and make our wastewater on site easy to treat; most is used to irrigate and fertilise nearby fields. Our goal is to create a circular system where we give back positively to the land rather than pollute it.
Finally, we produce all of our leather goods in small batches here in the UK. At Billy Tannery, the focus is always on the details. That’s why we only use vegetable tanning to produce our goatskin leather, to let the distinctiveness of this type of leather truly speak for itself.