PATHOLOGY

Detailed explanation-1: -The three most widely used tanning agents are vegetable tannin, mineral salts such as chromium sulfate, and fish or animal oil. See also leather. The oldest system of tanning relies on the chemical action of vegetable material containing tannin, or tannic acid, on the protein constituents of skin.

Detailed explanation-2: -There are three key tanning methods used to make leather: Chrome Tanning. Vegetable Tanning. Chrome-free Tanning.

Detailed explanation-3: -Tanning takes its name from the use of tannin in traditional methods. Tannin was extracted from the bark of certain trees. A more modern method, called chrome tanning, was developed in the 1800s and employs chromium salts instead of natural tannins to produce a similar effect.