High Quality Content by WIKIPEDIA articles! Tanning is the process of treating skins of animals to produce leather, which is more durable and less susceptible to decomposition. Traditionally, tanning used tannin, an acidic chemical compound from which the tanning process draws its name (tannin is in turn named for an old German word for oak or fir trees, which supplied it). Coloring may occur during tanning. A tannery is the term for a place where the skins are processed.