Methods and MaterialsGiven the symbolic importance of precious materials, it is not surprising that Himalayan artisans developed numerous ways to enrich devotional art. Mercury gilding and cold gold paint, as well as inlaid precious and semiprecious metals and stones, lavishly enhance the majority of Himalayan art, both Buddhist and Hindu. Even textiles are embellished with precious metals: thinly beaten strips of gold and silver are wrapped around threads and woven into luxurious brocades that adorn temples, paintings, and sculptures.
Lost-wax Casting and Repoussé
For the last one thousand years, Himalayan craftsmen have used the processes of lost-wax casting and repoussé to create metal sculptures. In lost-wax casting, a wax form is encased in clay, and then heated to melt the wax, leaving behind a hollow clay mold. Molten metal is poured into the mold and allowed to cool, forming a metal sculpture in place of the lost wax. In repoussé, thin sheets of metal are hammered into sculptural forms, in both high and bas relief.
Inlay and Mercury Gilding
Equally ancient decorative techniques are inlay and mercury gilding. Inlaid designs are created by hammering differently colored decorative metals (such as gold, silver, and copper) into metal grooves that have been enlarged to hold the decorative metal in place, or by placing stones into particular cavities and affixing them with a variety of resins. Mercury gilding is achieved by brushing a mixture of powdered gold and mercury on a metal sculpture after the surface has been cleaned with nitric acid. The coated piece is then suspended in a fire until the mercury evaporates, leaving an even gold finish. The brilliance of the gilding depends on how finely the gold is granulated.
The material known as cold gold first became popular in the Himalayas during the sixteenth and seventeenth centuries. Made by mixing finely ground gold with glue, it is often used to paint the face, neck, and occasionally the hands and feet of a sculpted figure or to embellish details in paintings. Gold is the last pigment added to paintings, and may be burnished (specially polished) for a higher sheen. However, this type of gilding tends to oxidize, darkening the color; over time the glue breaks down, causing the gold to flake off. In addition to decorating sculptures and paintings, devotees may take small amounts of cold gold paint to leave small drops as offerings to sacred images both in regular worship and for special occasions such as a successful pilgrimage.