The coloring of leather clothes is complicated, and coloring is the last process in the process of making leather. A piece of leather is softened, fleshed, sliced, tanned (leather conversion process), polished, painted, dried, ironed, polished, measured and packaged.
Then the leather is generally painted with a spray gun, put on a vented net cover, mixed with leather pigments for spraying, repaired with a brush, dried after spraying, and then sprayed with ordinary formaldehyde to fix the pigments on the leather.