It was invented in 1858 that chrome salts such as chromium sulfate were used as the main tanning agent to tanning leather. The tanning time and cost were much less than vegetable tanning leather. The leather tanned by this method was blue white, so it was called "wet blue leather".
Chrome tanned leather is soft and flexible, with little fading and shrinkage. It is easy to dye and sew. It is mostly used for making clothes or leather shoes. But this kind of leather will produce harmful substance "hexavalent chromium" after burning.
