Leather can be tanned in a variety of ways. But what is tanning? 'Tanning is the process of converting animal skins into leather by utilizing some form of "tannin". Leather produced today is usually chrome tanned, alum tanned or vegetable tanned.' Chromium tanned leathers have actually been shown to cause dermatitis. It is also a process that has a harsher environmental impact than vegetable tanned leather.
Vegetable tanning is the method of converting rawhide into leather with these plant-derived tannins. 'Tannins are yellowish organic compounds found in a wide variety of plants including the bark of oak, hemlock, quebracho, and chestnut trees. Hot water extracts the tannins making a tannic acid solution'. Tannins actually change the composition of skin fibres which makes them pliable, water repellant and resistant to bacteria. Because the process is more time-consuming, vegetable tanning is more often used for high-quality, expensive leathers. It is far less expensive to produce chrome tanned leathers. Vegetable tanning is technically the only natural form of tanning since tannins are from plants. It is usually better for the environment, but the manufacturer must also consider disposal methods about waste water and byproducts.
Original source on tanning: "Vegetable Tanned Leather." Http://www.negmaleather.com/. Negma Leather, 4 Oct. 2011. Web. 2 Feb. 2015. <http%3A%2F%2Fwww.negmaleather.com%2Fwhat-is-vegetable-tanned-leather%2F>.
Based on this research I choose to work exclusively with vegetable tanned leather. However, it has forced me to question my own practices. Is vegetable tanned leather really as eco friendly as it seems? What does the company do with any waste water? The website for Tandy Leather Factory states that 'Tandy suppliers shall commit to reducing the environmental impact of their designs, manufacturing processes, and waste emissions'. While thats a great statement, it is the only mention of environmental issues on the site and I would love to know more. I will follow up this post with more information after I make a few calls to Tandy to ask them for more details.
Quote from: "Tandy Leather Factory Supplier Code of Conduct." Supplier Code. © 2015 Tandy Leather Factory, 2015. Web. 02 Feb. 2015. <http://www.tandyleatherfactory.ca/en-cad/home/infoandservices/supplier-code/supplier-code.aspx>.