Question

Tanning of leather is the :

• A. colouring of leather by chemicals
• B. drying process to make the leather hard
• C. polishing of leather to make it look attractive
• D. coagulative hardening of the leather by chemicals

Answer 1

The correct option is D coagulative hardening of the leather by chemicals

Tanning is the process that converts the protein of the raw hide or skin into a stable material which will not putrefy and is suitable for a wide variety of end applications. The principal difference between raw hides and tanned hides is that raw hides dry out to form a hard inflexible material that can putrefy when re-wetted (wetted back), while tanned material dries out to a flexible form that does not become putrid when wetted back. A large number of different tanning methods and materials can be used. The choice is ultimately dependent on the end application of the leather. The most commonly used tanning material is chromium, which leaves the leather, once tanned, a pale blue colour (due to the chromium), this product is commonly called wet blue.