Chemically, the tannable pelt consists only of the main component of a hide that can be converted to leather, collagen: a fibrous connective tissue protein, the molecules of which are tightly interwoven to form an infinite three-dimensional fibre network that is ultimately decisive for the many natural properties of leather, especially its durability.
The tanning process
Based on the desired leather quality, the appropriate tanning agents are applied to this collagen in the subsequent actual tanning process. These react with the collagen in the aqueous environment to form leather which, unlike the original hide, is now resistant to rot and heat stress and can be stored and transported. The choice of tanning method is determined by the subsequent intended use of the leather, e.g. as shoe or furniture leather, for leather clothing or car interiors. While only vegetable tanning with plant extracts from chestnut, oak or mimosa is used for abrasion-resistant shoe soles, mineral chrome tanning is the tanning method of choice for upholstery, upper or fine leathers. Chrome-free tanned leathers are also available upon request.
The retannage (process)
In the subsequent processes of finishing, the final character of the leather is determined with the help of vegetable, synthetic or mineral retanning agents. This gives the leathers a better and more uniform fullness and makes further technical quality improvements.