Bidri derives its name from Bidar, the capital city of the bahamani sultans of the 16th century. The art is Persian in origin and is more than 500 years old, but Bidri is a purely Indian innovation. Bidri is cast with an alloy of zinc, copper and other non-ferrous metals and pretty designs are engraved with a grooving chisel. Thereafter it is inlaid with pure silver wire which is then polished with a buffing machine. The product is then dipped in a solution prepared out of the soil of the fort of Bidar which has special oxidizing properties. The zinc alloy then turns a lustrous black but the silver inlay stays intact to contrast beautifully with the dark background.