The term cordovan historically designates high-quality goat or billy goat leather , very light and soft, which was obtained through vegetable tanning with special substances, including tannins obtained from sumac .These tannins are more resistant to oxidation than other plant tannins, which helps maintain the leather's color for longer. They also allow for greater penetration of dyes, which is why this leather was used as a base for embossed and polychrome leathers . The word is of Mozarabic origin and refers to the city of Córdoba , famous for its tanning and all kinds of leather crafts. In Spain, the technique was developed during the Middle Ages and reached its greatest diffusion and renown during the 16th and 17th centuries