BIDRI (a specialized metal handcraft) is done in Andhra Pradesh. The basic material used is an alloy of 94% zinc and 6% copper. After moulding, the required article is filed and the surface smoothened. The design is then sketched and engraved on it. Pure silver wires and sheets are inlaid by hammering them into the engraved designs. After the silver inlay work is done, the item is filed, polished, buffed, and then oxidized.
The oxidizing is done with a solution containing a particular type of earth from the fort at Bidar (in Karnataka State – hence the name Bidri). As soon as the article is dipped into the boiled solution, the alloy surface of the article becomes jet-black and the silver remains as it is. The article is then lightly coated with coconut or groundnut oil, or any other lubricant, and polished with a soft cloth.