The basic material used is an alloy of 94% zinc and 6% copper and a special soil that is found only in Bidar, the state of Karnataka, Intricate inlay work involving pure silver, and a few other materials. Put them all together and what you get is magic.
Bidri craft originated in Persia and came to India in the 14th century, flourishing in Bidar, today’s Karnataka, under the Bahamani Dynasty. While in Persia, gold and silver was inlayed on steel or copper, in Bidri work, zinc is the primary metal used today.
The significance of the craft lies not only in its beauty, history and production technique, but also in a special ingredient- the soil from the Bidar Fort. This black soil is an important ingredient for Bidri work for it has special chemical properties; the soil has been away from sunlight and rain for hundreds of years and is used as an oxidizing agent.
A mix of soil, castor oil and resin is used to prepare a mould. Into this mould, the molten metal alloy of is poured. Depending on the design, different metal casting may need to be welded together to form one single product. Copper sulphate is then applied on the shiny surface, which causes it to become temporarily black in colour. This makes it easy for the craftsman to draw the designs clearly on the black surface which is etched using a metal stylus.
Artists who practice this craft have fingers that are so nimble and deft, that there is no room for error. Their chisels move smooth and effortlessly, with a practised ease and what emerges are delicate, striking patterns.
The piece is then handed over to the inlayer. The inlay may be of silver, brass or gold.
And then the product is ready for the final step of making the surface permanently black so that the silver inlay design stands out in bright contrast against the dark background.