Metal Image-casting in Nepal
Ian Alsop

The contribution of the Newar metal sculptors of the Kathmandu valley to the Himalayan art traditions has been long-lasting and profound. For centuries these artists have been the acknowledged masters of their trade, and even today they create many of the images used in worship by Buddhist communities throughout the world.

From the earliest metal sculptures we know until the present time, Nepalese metal sculpture has continued without a break in the Newar heartland of the Kathmandu valley. The patrons were likely to be either royal or members of the richer elements of the diverse and energetic Newar society. It would seem that in previous times, as today, the Nepalese metal sculptors were taken from the ranks of the Buddhist elite or priesthood, in particular the Sakyas of a few Buddhist bahals of Patan. It is likely that they provided fine metal icons for Bauddha and Saiva alike, for we have no indication that any Hindu group practiced this craft.1

The date of the earliest metal work from the Nepal valley is uncertain, but it is likely to precede by several centuries the sculpture of a standing Buddha in the Cleveland Museum, dated 591 CE, which is the earliest inscribed and dated metal sculpture known to us.2 The earliest sculpture in stone in Nepal is a second-century image of a king, which reflects Northern Indian Kushan dynasty style and taste.3 The technology involved in creating such a large stone sculpture would lead us to suspect that metalworking had also advanced sufficiently to allow the creation of sculpture in metal, but we have no specific examples to support this. In fact the earliest datable metal objects are the copper coins of the Licchavi kings, the earliest of which can be dated to somewhat earlier than the Cleveland Buddha. It is certainly likely that metal casting was practiced between the creation of the second-century Jaya Varma stone and the earliest Licchavi coins, and although there are no inscribed and dated examples there are several cast metal figures that might suggest pre-sixth century dates.

The metal casting and repoussé techniques of the Newar masters of the past can be seen in the work done by their worthy descendants, the sculptors of today who supply the demand of the tourist market and Buddhist communities in Asia and beyond. The technique of ‘lost wax’, or cire perdue is much as described by Marcel Nies in his introductory essay in the present volume, and can be observed in person in the casting centres of Patan or the Kathmandu valley. Even the casual visitor to the ancient Buddhist community of Oku Bahal, or Rudravarna Mahavihara, and to a lesser extent the community of Nag Bahal, will likely notice the telltale signs of cire perdue casters at work: the smell of burning beeswax and the tap-tap-tap of the hammers and chisels of the engravers and finishers who clean, smooth and engrave the sculptor’s work.

It is worth noting several special characteristics of this occupation as it is practiced today. Most sculptors in the West generally use a malleable material, usually clay, to produce the model for the casting, and have little or no participation in the actual production of the casting, a process they leave to technicians of a casting workshop. The Newar sculptors of Patan work directly in the wax which will later be burned out and evaporated in the cire perdue process, and they usually cast their own work. Occasionally they will produce to order wax models—either uncovered or already encased in a mould—for casting in another workshop. Once the rough sculpture has been cast, the sculptor hands it on to another group of artisans, the engravers, who smooth the rough surfaces and engrave the fine details.

There are a few other elements of the Newar casting technique that differ from standard casting practice in the rest of the world that are worth mentioning. The Newars have always cast their precious icons almost exclusively in a nearly pure copper. Pure copper is rarely cast in the West in modern times because the molten copper, no matter how strongly heated, never flows very easily and produces abundant gases, which tend to flaw the casting. The Newar casters avoid some of these defects through the use of relatively porous mould materials, which we will mention below. Modern Western casting technique calls for relatively non-porous mould materials. To vent gases, the pour is directed first to the lowest point of the casting via a main pour channel; the metal, once it reaches the bottom of the mould, then moves up through the rest of the sculpture while the gases produced by the process escape through vents at the top. The Newar casters eschew the relatively complex system of pours and vents that this system requires, instead opting for a simple system usually incorporating a tripod of channels for the pour leading directly to the sculpture, which does not have further venting. This system works largely because the mould material used by the Newars is a composite of fine clays mixed with various organic materials, notably rice husks in the outer layers and cow dung in the fine inner layers. These organic materials are burned out of the mould during the firing of the mould prior to casting and the mould becomes somewhat porous, allowing the gases to escape without vents.

While this exhibition concentrates on cast sculpture, it does contain a notable example of repoussé, a technique that was brought to a pinnacle of workmanship by the Newar craftsmen who worked throughout the medieval period. This technique is in some respects more challenging than cire perdue; whereas in cire perdue the sculptor is working with a soft and malleable material, wax, which is very easy to manipulate, in repoussé the material is sheet copper, which must be manipulated by strenuous hammering followed by delicate engraving. The material and technique is unforgiving of mistakes, for once a mistake has been made –pushing a section of the sculpture too far out from the plane, for instance—it is difficult to rectify. The example that we see in this exhibition (cat. no. 40), testifies to the virtuosity of the Newar sculptors who worked in this technique. There is no doubt that the Newars were among the masters of this technique worldwide and throughout history, and I have never encountered work from other traditions to rival the best of the Newar repoussé.

Another element of Newar metalwork that should be mentioned is the post-casting finishing work. Newar metal sculpture of religious icons almost always uses pure copper and the copper is almost always gilded. The gilding method used is the dangerous technique known as ‘mercury gilding’—now illegal in most countries. An amalgam of gold and mercury is applied to the surface of the sculpture, usually with a brush, and then a high heat is applied via a torch and the mercury is burned off, leaving the pure gold, which is then burnished to a high gloss. But the process of burning off the mercury produces a lethal mercury vapour, which is why it is illegal in most countries. The Newar gilding craftsmen are aware of the dangers of the vapour, and feel that some protection is afforded by stuffing their mouths with raw meat during the process and staying upwind of the torch; nonetheless, mercury illnesses are common among the workers who specialize in the gold and mercury work. The creation of the mercurygold amalgam used in gilding copper is a closely guarded cultural secret known only to the Newars themselves; the production technique is similar to that used to produce the gold paint used by painters to embellish thankas and to paint the faces of Tibetan statues. To this day, those seeking to acquire the mercury-gold amalgam used in cold gold application and thanka painting must address themselves to a single shop in Kathmandu where this product is sold.

Another element of Newar metal sculpture that draws the attention of the viewer are the delicately inlaid precious and semi precious stones that dot the shining gold surface of these statues. The stones are varied, including lapis and garnet or spinel ruby, and sometimes artificial—instead of using turquoise, for instance, many Newar craftsmen preferred glass stones in blue and green. The stones are meticulously shaped —round, square, rectangular, teardrop or arabesque—to fit the miniature settings which are cleverly worked to receive them, and the overall effect is stunning. Surely there is no more luxurious tribute to the power of faith in South Asia than the often diminutive Newar sculptures, delicately cast, finished in pure gold and studded with a myriad of precisely set stones of many colours.

Largely because of the extraordinary skill that the Newar metal workers seemed to have genetically imprinted, they were very popular with patrons throughout the Himalayas. In Tibet in particular, the highest lamas—able to accumulate considerable wealth for their monasteries through the faith of their followers and the feudal system of support for religious institutions—sought out the Newar metal sculptors and their fellow artists the painters to complete projects both small and immense. That Newar metalworkers were known in Tibet for many centuries is attested by one of the earliest of the Tibetan chronicles, which mentions the ‘Bal-po’, the Tibetan term for the Kathmandu valley-dwelling Newars, as the ‘kings of bronze’ or providers of metalwork to the Yarlung dynasty emperors of the sixth to eighth centuries.4

The itinerant Newar artists were a fixture of Tibetan cultural life for centuries. They travelled to Tibet in search of fame and fortune, and often settled there, taking on a Tibetan wife and fathering mixed children. These children, half-Tibetan and half-Newar, almost always remained behind in Tibet if their father retired to the valley. It is certainly likely that these children and their descendants, Tibetans in name, language and cultural affiliation, carried on the traditions of the Newar metalworkers as taught them by their father or grandfather. The Newar metal sculptors also had an important impact in other smaller markets in the Himalayas, including the western Nepal Khasa Malla kingdom of the thirteenth-fourteenth century and the small kingdom of Mustang, both of which developed independent casting traditions with the Newar style and technique as a clear starting point.

The tradition of the Newar masters continues to the present day. Certain elements of the technique have been lost, notably the extraordinarily fine and delicate stone settings, and the production of the present cannot be compared in virtuosity with the great metal sculptures of the pre-medieval and medieval periods. But the art and craft of producing metal icons still continues among the Sakyas of Patan who to this day provide fine metal work to visiting tourists and to the Buddhists of the world.

1. For general studies of the technique and process of image casting in Nepal, see Ian Alsop & Jill Charlton, ‘Image Casting in Oku Bahal’, in Contributions to Nepalese Studies, vol. 1, no. 1, December 1973 pp. 22-49, and Marie-Laure de Labriffe, ‘Etude de la Fabrication d’une Statue au Nepal’, in Kailash, vol. 1, no. 3, 1973 pp. 185-192
2. Slussser, M.S. ‘On the antiquity of Nepalese Metalcraft’, Archives of Asian Art, XXIX (1975-1976), fig. 5: Ulrich von Schroeder, Indo-Tibetan Bronzes, 1981, Hong Kong, Visual Dharma Publications, pl. 74E, p. 304-305, (eleventh century).
3. Kashinath Tamot & Ian Alsop, ‘A Kushan-period Sculpture from the reign of Jaya Varma-, A.D. 184/185’, Kathmandu, Nepal, July 10, 1996, in Asianart.com: http://asianart.com/articles/jaya/index01_12.html; and another version in Orientations, September, 2001
4. see Guiseppe Tucci, Preliminary Report on Two Scientific Expeditions to Nepal, 1956, Roma IsMEO, where he cites the dPao gtsug apren ba, Tibetan Chronicles, p. 86.