Leather is a durable and flexible material created by the tanning of animal rawhide and skin, often cattle hide. It can be produced through manufacturing processes ranging from cottage industry to heavy industry.
The leather manufacturing process is divided into three fundamental sub-processes: preparatory stages, tanning, and crusting. All true leathers will undergo these sub-processes. A further sub-process, surface coating can be added into the leather process sequence, but not all leathers receive surface treatment. Since many types of leather exist, it is difficult to create a list of operations that all leathers must undergo.
Tanning is the process which matches 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.
Crusting is the process by which the hide/skin is thinned, retanned, and lubricated. Often a coloring operation is included in the crusting subprocess. The chemicals added during crusting must be fixed in place. The culmination of the crusting subprocess is the drying and softening operations.