The classical art of bronze-casting was perfected by craftsmen who rendered religious imagery into metallic form.
Slender images of goddesses rich in detail and mighty gods in awe - inspiring postures are created and each pose or gesture has a mythological significance. Stylistically the images made in Tamil Nadu conform to periods like Pallava, Chola, Pandyan and Nayaka. Bronze contrived from copper and tin is used to shape the beautiful sculptures following the guidelines in Shilpasastras.
While making the countless and individualistic images with extreme precision, the craftsman has to learn not only the physical measurements to achieve the right proportions but also to familiarise himself with the verses describing each deity, its characteristics, symbolism, and above all the aesthetics. Usually a coconut palm leaf is used as a measuring ribbon, marks being made by folding the leaf. On the technical and aesthetic excellence of the wax model depends the ultimate perfection of the end product. The mould is given several clay coatings on the wax model. In solid casting the molten alloy is poured in a thin and even stream into the mould. When the mould is broken, care is taken to see that the head of the icon comes out first as a good omen. Connecting rods are often used for support and these have to be detached most skillfully. In hollow casting a clay model is made over which is applied a thick coating of prepared wax. The thickness of the wax must match that of the final article under preparation. The mould is kept rotating on the lathe as the hot wax is spread, over which are marked and pressed the designs for decorating. Other coatings are given of a paste of burnt clay to keep the wax intact. An opening is provided in the outer-shell and when a fire is lit around it the wax melts and flows out through it. Into this empty space is poured the molten metal. Then the usual method of tempering it with heat and cold alternately is operated.