Bidriware Office Set-B104075.Bidriware is cast with an alloy of zinc,copper and other non-ferrous metals.Pretty patterns are engraved on the casting inlaid with pure silver wire.The casting is then soaked in a solution mixed with the soil of bidar fort which has special oxidising properties.This causes the Zinc alloy to turn into a lustrous black,leaving the silver inlay intact to contrast stunningly with the black background.