In Tamil Nadu, Swamimalai artisans keep alive Cholas’ lost-wax casting technique

Master bronze-workers here maintain the thousand-year-old art of panchaloha (five-metal alloy, primarily used in Hindu iconography for making idols and jewellery) idol creation, each piece carrying forward ancestral knowledge. The foundries or the workshops present an extraordinary window into the process of crafting the sacred sculptures.

Starting with open courtyards, locally known as Muttan, where patinated bronze deities await completion: Murugan wielding his divine spear, Lakshmi seated upon her lotus throne, Krishna with his flute, Hanuman in devoted prostration, and Dakshinamurthy in his teaching pose.

Lost-wax casting transforms wax models into bronze sculptures through a process that melts away the original wax form. This ancient technique, known as Cire Perdue or investment casting, allows artists to create precise metal duplicates of their original designs.

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Passed down through centuries in Tamil Nadu, the Chola lost-wax casting technique offers an ingenious method for creating intricate bronze sculptures. “The process, perfected during the 10th–13th centuries, remains virtually unchanged today,” notes Suresh Rajan, owner of Rajan Industries.

He adds: “Converting wax to bronze requires a complex sixteen-step procedure where technical precision is essential. Every phase must be executed perfectly, since errors can destroy the entire piece.”

The process starts with creating a detailed wax model using a blend of beeswax and natural resins. According to Rajan, “Our artists mix pure honey beeswax with gum tree resin in equal parts, producing a workable material that sets quickly. We also use coconut oil for the modelling material.” 

At this stage, the artists must perfect every detail — from jewellery to facial expressions — since the wax will be destroyed in the casting process. The main body requires a harder wax mixture containing less oil, whereas delicate details and ornamental features use a softer, more oil-heavy blend.

“The next step involves attaching wax rods to the model, creating channels that allow molten bronze to flow in and air to escape during casting,” demonstrates sculptor Tarun, step-by-step. “Rod placement is critical to achieving high-quality casting results,” he adds.

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The wax model receives multiple clay coatings in the third stage. As Rajan describes, this clay comes from the lower Cauvery River region and contains natural salts that provide optimal characteristics for bronze work. The mould develops through successive clay coats, each requiring full drying before the next application.

“Solar curing follows for exactly one week, a duration determined by generations of craftsmen,” notes Tarun. Complete dehydration is critical to prevent mould failure and dangerous steam reactions when heated.

Pravin, another sculptor, who has been with the foundry for nearly a decade, demonstrates the fifth phase which involves heating the dried mould in a kiln fuelled by cow-dung patties and selected firewood. “Heat causes the wax to melt and escape through the channels, hence the term ‘lost wax casting’ — the wax pattern is eliminated during the procedure,” notes Pravin.

Due to Chola’s perfection of this method, it became known as ‘Chola lost wax.’ The sculptures they produced showcase unparalleled refinement and are considered among India’s most significant artistic achievements.

“Mould preparation for casting forms the sixth stage, where the hollow form is either buried in a pit or braced securely. This setup prevents movement when molten metal is poured, ensuring casting accuracy,” shares Tarun.

Kumar, a senior master artist, demonstrates the seventh stage: melting the metal — a process rooted in generations of metallurgical skill. Standard bronze contains 84% copper, 14% zinc, and 2% tin, though temple pieces often include traces of gold and silver. “Chola bronzes use 90–95% copper, brought in from outside Tamil Nadu,” he explains.

Step eight marks the culmination of weeks of work: the bronze, heated precisely to 1500°C, is poured into pre-warmed moulds with ritual care. Rajan notes, “Temperature control is everything — too low, and you lose detail; too high, and the mould fails. It’s a balancing act of science and instinct.”

The ninth phase involves controlled cooling, during which the molten metal solidifies within the mould over several hours, depending on the sculpture’s dimensions. Premature contact with the casting results in severe thermal burns.

The tenth step requires removing the mould by breaking away the cooled clay to reveal the bronze casting inside. This critical reveal determines the success or failure of the entire process, as any flaws in the casting become immediately apparent upon extraction.

Tarun says, “The eleventh step is cleanup — we cut away excess metal from the casting, and that’s when the sculpture starts shedding its raw shell and revealing its form. In step twelve, we refine the surface — filing, smoothing, burnishing — until the bronze begins to glow. Then comes step thirteen: detailing. This is where the magic happens — carving expressions, finger joints, ornaments — bringing the sculpture to life, one line at a time.” 

Tarun demonstrates the fourteenth step — final touch-ups ensuring perfect symmetry and adherence to classical iconography, where even the tiniest flaw is corrected. Next comes patination prep, the fifteenth step, involving meticulous cleaning through brushing, solvent washing, or thermal conditioning.

“The bronze demands complete cleanliness before its final transfiguration,” he says. In the sixteenth and final step, patina is applied using traditional compounds like cow dung, tamarind paste, or herbal blends.

“We usually go for Green Patina for an aged look or Wood Patina for warmer tones,” Rajan explains. Work begins only on spiritually auspicious dates, and the final ritual anchors the sculpture to its base — sealing in the Chola sheen.

“The cost of an authentic Chola bronze mirrors the time and skill behind it,” says Rajan. “Even a small piece takes 30–40 days; a modest two-footer needs 50–60 days. Larger temple sculptures can take six months to a year. Prices range from Rs 2,000 for simple items to over Rs 2 lakhs for intricate commissions.”

These numbers highlight the challenge artisans face. Mass-produced pieces may be cheaper and faster, but authentic Chola bronzes remain handcrafted masterpieces, valued by discerning buyers and temples for their craftsmanship, not convenience.

In her article titled “Chola Bronzes”, Aparna Joshi, a researcher, highlights, “Chola Bronze idols stand out from contemporary idols being made at the time for their distinctive manner of casting and alloys used. They were cast using a technique known as the Lost Wax Technique.” 

Whereas Vidya Dehejia, one of the foremost authorities on Chola art, highlights their significance, “There is nothing quite like these images anywhere else in India… their sheer physical perfection of form was seen as a reflection of spiritual beauty and spiritual purity.” She further contextualises the cultural role of the bronzes — portable in temple rituals and public festivals, not just static displays.

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Chola bronzes from Swamimalai now grace major museums worldwide, including the Smithsonian’s National Museum of Asian Art and New York’s Metropolitan Museum. At the Smithsonian, the exhibition “The Sensuous and the Sacred: Chola Bronzes from South India” at the Sackler Gallery featured around 70 temple bronzes, many cast in Swamimalai, including Shiva Nataraja, Uma, and Ganesha, highlighting their ritual value.

The Met, on the other hand, houses notable Chola bronzes, such as the 11th century Hanuman Conversing, Shiva Tripuravijaya (Shiva as Vanquisher of the Three Cities), 10th century Standing Parvati, and “Standing Vishnu” (third quarter of 10th century), each a hallmark of Swamimalai’s temple bronze tradition.

In 2025, Swamimalai remains a paradox in motion — here, foundries are more than production sites; they’re classrooms, sanctuaries, and social laboratories. Rajan Foundry alone trains hundreds of students each year, continuing the guru-shishya tradition through observation and hands-on practice.

The state-run school, admitting 15 students every three years, owes its existence to the sthapathis, yet today, not all artisans come from this lineage. Take Rajan, who was once disowned for choosing bronze over stone, and is now a torchbearer for modernity and generosity. Swamimalai is no museum; it’s a living dialogue between legacy, enterprise, and change.