Tanning
Tanning is the process of making leather from skin. This is commonly done with the acidic compound tannin which prevents normal decomposition and often imparted color.
During the ancient period tanning was considered to be a noxious trade and relegated to the outskirts of town, amongst the poor. Leather was used for waterskins, bags, harnesses, boats, armor, quivers, scabbards, boots, and sandals. Around 2500 BC, the Sumerians began using leather, affixed by copper studs, on chariot wheels.
Tanners would take animal skin and soak it in water, then they would pound and scour the skin so as to remove flesh and fat. Next they either soaked the skin in urine to loosen hair fibers or they let the skin putrefy for several months, after which they dipped the skin in a salt solution. After the hair fibers were loosened the tanners would scrape them off with a knife.
Once the hair was removed, tanners would bate the material by pounding dung into the skin or soaking the skin in a solution of animal brains. They would also take cedar oil, alum, or tannin and stretch the skin as it lost moisture and absorbed the tanning agent.
Leftover leather would be turned into glue. Tanners would place scraps of hides in a vat of water and let them deteriorate for months. The mixture would then be placed over a fire to boil off the water.
Sun tanning is the browning of light-colored skin by exposure of the bare skin to sunshine. To avoid sunburn tanning oil or creme is used.History of Tanning
