Crust leather is a leather dried after tanning but not been dyed. When it comes to chrome-tanned leather, it is known as “chrome crust” and, for vegetable-tanned leather, as “vegetable crust”. Crust leather is rarely processed. Generally, the leather is dyed and finished before processing.
Crusting is the most important part of crust leather production. The main stages of the crust leather production process are called, preparatory stages, tanning, crusting and surface coating.
The crusting process starts the time when the hide is thinned, re-tanned and regressed. Often a dye method is included in the crusting. Also, part of the crusting process includes drying and softening.