The basic material of Bidriware is an alloy of zinc and copper in the proportion of 16:1. It is on this alloy that artistic designs in pure silver are engraved. The Bidriware undergoes an eight-stage process. The 8 stages are molding, smoothening by file, designing by chisels, engraving by chisel and hammer, pure silver inlaying, smoothening again, buffing and finally oxidizing by soil and ammonium chloride. Now the Bidri item is ready for the final step of making the surface permanently black so that the silver inlay design will stand out in bright contrast against the dark background. There is a particular type of soil found in the inner depths of ruins which are three hundred years old, in buildings where neither sunlight nor rain has fallen for hundreds of years. This soil, when mixed with ammonium chloride and water, produces a very special paste which is rubbed onto the heated Bidri article. The paste darkens the body of the piece, but has no effect on the silver inlay. As the paste is rinsed off, the design springs dramatically into view, the shining silver resplendent against the black surface. Finally, oil is rubbed on the piece to deepen the black matt coating. KSHDCL has registered Bidriware under the Geographical Indication Registry – No. 20.