Technology of Medieval Crafts: Bidri Ware
by D.P. Agrawal & G.S. Dashila
The tradition of arts and crafts in India goes beyond five thousand years. The exquisite stone and metal sculptures and the lapidary craft of the Harappans are examples of the virtuosity of the Indian craftsmen. We may take just one example of the Harappan technology: the gold granulation technique. Minute spheres of gold were soldered on to the surfaces of ornaments or ceremonial objects. In our century, European jewellers tried to revive this technique but found it particularly difficult to make spheres as small as those on the Harappan artefacts, and to solder the spheres without spoiling the surface. It took years of trial and error to develop a glue of metallic and organic ingredients that worked on a metal surface.
A number of traditions of crafts based on metals, alloys, gems and stones flourished in ancient India. Many of these traditions started in ancient India and continue vigorously even in modern India. Here we will talk about some medieval crafts.
The Bidri Ware is valued for its fine craftsmanship. Its sleek and smooth dark coloured metal work with intricate eye-catching designs on its glossy surface is famous all over the world.
Basically Bidri is a brass alloy, which contains zinc, copper, lead, tin and traces of iron. The usual yellow brass may contain not more than 40-50 per cent zinc. Copper constitutes the predominant phase. The brass and Bidri Ware represent two opposite ends of the zinc-copper phase diagram.
After making the surface smooth, a solution of copper sulphate is applied to the Bidri Ware to darken it temporarity for engraving. The engraving tools cut the intricate but delicate tapestry of design into the metal, which is then lighter in colour. The piece is then handed over to the inlayer. The inlay may be of silver, brass or gold. The surface of the decoration blackens after the inlay has been burnished. This is done by applying a paste of ammonium chloride, potassium nitrate, sodium chloride, copper sulphate and mud which darkens the body by producing a characteristic black patina, but without damaging the inlay.
La Niece and Martin carried out replication experiments and found that the black colour of the patina was due to copper. In a replication experiment a clean pure zinc sheet was immersed in the above solution, which produced a pale grey patina of zinc oxide and chloride. When the experiment was repeated with the addition of copper sulphate, a reasonably good but superficial black patina formed. XRD analysis identified Zn5 (OH)8 Cl2, H2O, ZnO Zn and Cu2O in crystalline phases.
La Niece and Martin have postulated that ammonium chloride preferentially dissolves the zinc from the Bidri Ware and the resulting copper-enriched surface gets oxidised by potassium nitrate producing the black colour. The mystery of the black patina has not yet been fully solved. How the ancient craftsmen developed such intricate chemical procedures is difficult to imagine.
The craft of Bidri Ware is a kind of damascene work, which has been defined by Sir Georgy Birdwood as “the art of encrusting one metal on another not in crustae, which are soldered or wedged, but in the form of wire, which by undercutting and hammering, is thoroughly incorporated into the metal which it is intended to ornament…” The original tradition at Damascus was to encrust gold wire, and sometimes silver wire on the surface of iron, steel or bronze.
Historical evidence indicates that the beautiful articles presented to Alauddin Bahamani II (AD 1434-57) on the occasion of his coronation impressed him so much that he invited the craftsmen of Bijapur to settle at Bidar itself. The Russian traveller Althanasins Nikitin, who visited Bidar during AD 1470-74, took with him some of the early Bidri Ware specimens for presentation to the Russian Emperior. A large number of articles of Bidri Ware were made for presentation to the Prince of Wales when he visited India in 1875. Thus the glory and fame of the Bidri ware spread far and wide. Bidar and Hyderabad museums also have beautiful collections of this kind of ware.
Mahmud has given some details about this craft under specific headings such as raw materials, tools, implements, process of production, preparation of alloy, mould making etc. The moulder prepares the alloyed metal, casts the vessel and turns it to its proper shape using his lathe. In the pre-modern India there have been four notable seats of Bidri Ware manufacture: Bidar, Lucknow, Purnea (Bihar) and Murshidabad.
Modern Indian industries started with machineries, and therefore Pramatha Nath Bose rightly defined his treatise on pre-modern ‘Art industries in India’ as the ones carried on without the help of steam or machinery except of the simplest kind.
During the medieval period, guns were made of wrought iron, brass and bronze. The Malik-i-Maidan was a gun cast at Ahmedangar in AD 1548 and has been described as the ‘largest piece of ordnance in the world.’ Vessels of brass and bell metal were made in eighteenth/ninenteenth-century Bengal, in places such as Khankra near, Murshidabad, Jhanjharpur near Darbhanga, Kanchannagar in Burdwan, Islamabad in Dacca, Bansberia in Hughli etc.
The Varanasi brass ware with its excellence of the cast, rich colouring, gold like lustre, etc.was probably the best in India.
Yajnavalkya mentions that tin and lead vessels could be cleaned with alkali and acid water, whereas copper alloys like kamsya (bronze) and brass should be cleaned only with ash and water (Acaharadhyayaya 190).
Along with the Bahmani coins (AD 1347-1500), a copper contatiner with both internal and external coating of tin has been discovered in the archaeological excavations at Brahmapuri. Sanskrit texts of medieval period refer to tin as kalhai/kalaya.
In the districts of Ahmadanagar, Pune, Satara, Solapur,Belgaum Dharwar, Bijapur and Nasik the Bombay Gazeteer of 1904 contained notes on kalaigars, a caste of Muslim tinsmiths.
Crafts in Nobel Metals
Bose reported artisans of Dacca and Cuttack making beautiful gold silver plates, filigrain jewellery and other filigrain works. Silver plates made at Bhowanipur were quite famous. In silver wares the ornaments were engraved, while in others they were beaten out (repousse). Tonk in Rajasthan used to produce gold and silver plates ‘good in design as well as in execution.’ Bikaner had sheltered merchants and artisans fleeing from the pillage of the latter day Moghuls and Mahrattas and they in turn initiated excellent traditions in crafting silver and gold art objects. No part of India was however more celebrated for its work in precious metals than Kachchha in Gujarat.
Gold and silver wires were used in lace-making and kalabatun in the weaving of brocades. Cloths of gold and silver saris made at Baluchar near Murshidabad, bedecked with flowers and figures were highly appreciated by the Bengali ladies.
Employing the Damascene technology, the Tanjore metal work consisted of soldering, wedging or screwing of silver patterns and figures of deities on copper vessels. ‘The white figures in the famous Swami style on red copper ground reproduced an effect at once bold and striking.’
Another art tradition in India that survived through the ages was setting of precious stone on jewelleries. Skiful murassiakar or jewel-setter used his skills on massive golden jewellery.
Recovery of Precious Metals from Waste
Indians evolved methods for recovering, purifying and re-using precious metals. Thakkura Pheru and Abul Fazl have described crude techniques for purifying and assaying gold and silver objects. Gold could be recoverd by an amalgamation procedure; smelting with lead gave recovery of silver.
A simple step of purification consisted of heating the impure metal in a charcoal fire to redness and then suddenly cooling the metal by sprinkling water so that copper could not get reoxidised. During the eighteenth/ nineteenth century there were two categories of people earning their livelihood by recovering gold from the refuse. They were known as neharwala and jamakwala.The neharwalas collected the daily sweepings from the goldsmith’s shops. Jamakwalas used to collect jamak or the waste liquid, which was obtained during the purification of gold as well as its cleaning and colouring processes involving gold ornaments. The jamak or the waste liquid was found on analysis to contain chlorides, nitrates and sulphates of silver, copper, zinc, gold, aluminium, potassium and sodium.
The Craft of Minakari
The art of enamelling or fixing colour by melting in fire has been practised in India ever since the ancient times. During the medieval period, there were many techniques employed for colouring ornaments and other objects of gold and silver and also other metallic objects made of copper, brass, etc.
The art of enamelling jewelleries was practised by a special class of artisans known as minakara. Jaipur was most famous for enamelling work on gold, followed by Varanasi, Alwar and Delhi. The enamelling of gold in Multan, Shang and Kangra was generally of dark and light blue colour, the blue vitreous enamel being the most common. Multan, Bahawalpur, Kashmir, Kangra, Kulu, etc. had traditions of enamelling on silver.
Jaipur was famous for enamelling work not only on golden ornaments but also on other wares made of this precious metal. The crutch staff on which Maharaja Man Singh leaned when he stood before the throne of the Emperor Akbar at the close of the sixteenth century has been vividly described: “It is fifty-two inches in length, and is composed of thirty-three cylinders of gold arranged on a central core of strong copper the whole being surmounted by a crutch of light green jade set with gems…Each of the thirty-two upper cylinders is painted in enamel with figures of animals, landscapes and flowers.”
The arts and crafts in pre-modern India based on metals, alloys, gems and minerals had attained global fame. It is surprising how the Indian art and craft objects were marketed globally through ages. Some of these traditions are still surviving and likely to continue through the twenty first century.
Biswas, Arun Kumar. 2001. Minerals and Metals in Pre-Modern India. New Delhi: D.K Printworld (P) Ltd.
1. S. Stronge, Bidri Ware, Inlaid Metal-work from India, Victoria and Albert Museum, London, 1985.
2. T.R. Gairola, Bidri Ware, Ancient India, 12,1956, pp.116-18.
3. Sayed Jafar Mahmud, Metal Technology in Medieval India, Daya Publishing House, Delhi, 1988. Chapter 14 (pp.115-26) is devoted to ‘Bidri Metallurgy’.
4. S. La Niece and G. Martin, The technical examination of Bidri Ware, Studies in Conservation, 32, 1987, Pp. 97-101.