Vegetable-tanned and animal-friendly leather is tolerable on KAP, while chemical-tanned leather is not.
Tanning is an obligatory step in turning hides into leather. It makes them unalterable, stronger and can be made softer or stiffer.
Vegetable tanning is a natural technique using plants such as wood, bark, berries, leaves, etc. as they contain natural tannins. The waste water from these baths is therefore biodegradable. Vegetable tanned leather is an alternative to mineral tanned leather which uses chromium salt and aluminium which is dangerous for the people handling it and pollutes the ground water when this water is discharged as it is into the environment.