This instalment will look more closely at vegetable tanning materials and methods. Vegetable Tanning Types of Vegetable Tanning Material Soluble components present in the bark, leaves or fruit of very many different species of plants have been found to have tanning properties.
Good control is essential to ensure consistency.
Two commonly used examples of catechol tanning extracts are Mimosa , and Quebracho . In addition, the oxidation which takes place as the leather ages gives rise to acidic by-products which attack the structure internally, weakening the fibres and ultimately causing complete loss of strength. Nevertheless, this breakdown is usually fairly slow and products made with this type of leather can have many years of useful life. The pyrogallol materials tend to have a lower astringency which means that they are able to penetrate into the pelt very well before fixation takes place. This produces a deep tanning action and a mellow leather.