What is Vegetable Tanned Leather?
Vegetable tanned leather is one of the oldest processes of treating and preserving leather. Its name reveals exactly what it is made of – vegetables! Well more like vegetable roots and tree bark. Also known as bark tanning, its one of the most natural methods of tanning and preserving leather. All those old leather saddle bags or messenger bags you find at flea markets are probably made of vegetable tanned leather. But it history goes way before that, starting around the time of the ancient Egyptians it traveled to Europe and England where the technique was refined and came to the Americas with the colonists. Some of the tanneries we have in the East coast share that lineage.
How do vegetables roots and tree bark preserve leather?
The word “tanned” actually comes from Tannin. Tannin is an asringent molecule found in most plants that bonds readily with proteins. It helps tighten the pores when leather is bathed in a tanning bath. When the pores tighten on the hide, it seals the top layer creating a waterproof barrier. Trees have the more tannin in their bark than the average plant. Embedded in the bark, the tannins protects the the tree from micro organisms and funghi. As the leather is tanned bacteria is also killed in the bath. Rendering it as a usuable material for other purposes. The softness of the leather is achieved by using different tanning methods. Typically Oaks, Fir, some Willows, Chestnut, Sumac leaves, Canaigre root, Birch, Alder, Hemlock trees are used for bark tanning. The end color of the hide depends on the type of tree or vegetation you use.
What makes it so special?
The history of this material and its natural provenance is pretty cool in itself. Beyond that, the natural tanning process also leaves no protective coating, leaving it vulnerable to the environment. This “nakedness” is what makes it special. Without any additive protective coating the hide will not stay in its pristine light state. As it gets exposed to the environment, the surface of the hide darkens. Oils from your hands conditions the hide, softening and creating darker areas where you interact with it most. And yes sometimes it will get wet and that too changes the material. All of which adds character to the material, making every piece one of a kind!