Large animals like cattle have hides, while smaller animals like pigs and calves have skins. The technical differentiation occurs at the fifteen pound point. Hides must be processed to produce leather. This processing includes pre-tanning, tanning and finishing. The pre-tanning process involves soaking, cleaning and washing the split hides.
Tanning is done by vegetable or chemical means and in some cases a combination of the two methods.
The vegetable tanning process is performed by placing the sides in large tanks of oak bark tanning solution for several days. The chemical process involves adding salt to water in large tanks and then adding chromium salts. The pelts are then added and turned for several hours. The finishing process involves washing and rinsing the pelts and then smoothing and pressing them. The tanning process converts the collagen in the hide into leather.