Tannins are the essential elements in a wide range of uses discovered over the centuries. Without any doubt, the oldest and most important one is related to tanning hides to make leather suitable for garments, furnishings, leather goods, car interiors, leather soles and shoe uppers.
The term “tannins” was used for the first time in 1796 to indicate a substance present in vegetal extracts and able to build insoluble complexes with proteins of animal skin. Tannins are gathered from many types of trees and plants and can be present in barks, leaves, wood and also in fruits and roots. Only tannins are able to give tanned leather these unique characteristics that make them so special and distinguishable. The “smell of leather” is something typical and unique.
Tannins and their characteristics
In today’s tanning process, tanners use vegetable tannins in both liquid and powder form. The most famous and ancient extract is obtained from the chestnut wood. This one is mainly used to produce leather for soles. But also the quebracho extract, a tree that grows in the Chaco region in Argentina, is used in tanning process: in this case the extract gives to the leather an unmistakable reddish shade, a warm touch and a bright appearance.
In addition to chestnut and quebracho, Tara tannins are mainly used in car industry and upholstery. This extract provides to the leather excellent properties: wholeness, softness, good resistance to light and to heat.
Mimosa extracts, that give to hides a special pink colour, are especially suitable for shoes uppers, leather soles and leather goods. Gambier extracts, currently less used, are suitable for full grain and fine valuable articles.
Today a wilderness retreat and a slowdown to the use of chemicals, thanks to the deep changes in research, make tannins an important natural component for a wide range of industrial applications.