‘Thermocol Out, Clay & Shola In’: These Kolkata Artisans’ Durga Idols Won’t Choke the Hooghly This Pujo

Thermocol is a lightweight synthetic foam used for chaal backdrops, crowns and ornaments. Shola is the soft pith of a plant, traditionally shaped into delicate decorations. The difference matters after immersion, when synthetic materials can remain as debris while natural craft materials fit Kumartuli’s older traditions.

Koushik Ghosh is working toward idols decorated with shola, natural clay and natural colours instead of thermocol. Earlier artisans used bamboo, straw, jute, shola and natural pigments. Shola can produce detailed work, but it takes more time and skill than thermocol, which is quick to cut and relatively inexpensive.

The change is difficult because artisans must keep decorations affordable and meet festival deadlines. Gopal recalls that shola was beautiful but slower. Koushik’s approach tries to reduce waste while preserving the hand-built character of Durga idols and the livelihoods connected to Kumartuli’s workshops.

Around 5,200 Durga idols were immersed across 34 major Hooghly ghats and approximately 30 other water bodies in Kolkata and nearby suburbs in 2025. That figure shows the enormous scale of the festival’s yearly immersion process.

Immersion is the ritual conclusion for thousands of idols made in workshops such as those in Kumartuli. Each idol carries bamboo, wood, straw, clay and decorative materials into the water. Civic workers then clear debris from the immersion sites, especially where decorations remain behind.

The number also explains why material choices matter beyond one workshop. Thermocol and plastic decorations require careful collection and disposal because they can persist in the environment. Neel, a volunteer cleaning near Babughat, found thermocol floating, coloured residue near banks and plastic decorations collecting along the ghats.

A traditional Kumartuli idol begins with the kathamo, a bamboo-and-wood framework tied with jute rope. It supports Durga, accompanying figures, the lion and other elements. Artisans then perform khar bandha, tying straw around the frame to shape the body. Correct tying helps prevent imbalance and clay cracks.

The first layer is entel mati, sticky clay mixed with rice husk, or tush. It dries for about three to four days. Artisans add finer bele mati next, then allow another five or six days for drying, depending on weather. Cracks are repaired with fresh mud. Faces, hands and other delicate parts may be shaped separately in chhach moulds.

The final detailing includes chokkhudaan, or painting the eyes. Some artisans specialise in it because tiny brushstroke differences can change the figure’s expression. The method has stayed familiar across generations, although decoration and finishing materials have changed.

When idols are immersed, their decorations enter the Hooghly and other water bodies. Clay, straw and the idol’s framework become part of the debris that civic workers clear. Thermocol and plastic are more difficult because they can persist in the environment and require careful collection and disposal.

Neel, who has cleaned the Hooghly’s banks near Babughat for several seasons, saw thermocol floating on the water’s surface. He also remembers coloured residue near the banks and plastic decorations gathering along the ghats. These observations show how decoration materials remain visible after the ritual.

The article does not quantify chemical effects or long-term ecological damage. It does show a practical burden: workers must remove synthetic waste from immersion sites. Koushik’s move toward clay, shola and natural colours aims to make decorations less wasteful while keeping the craft affordable.

Idol makers adopted thermocol, synthetic paints and plastic ornaments mainly for practical reasons. Thermocol was lightweight, easy to cut and relatively inexpensive. Synthetic paints produced brighter colours. Plastic jewellery also offered a quick way to add decoration as demand for idols increased.

The contrast with traditional work was significant. Shola, cloth, zari and daaker saaj created detailed, traditional finishes, but shola required more time. Natural decorations made from jute, handmade paper pulp, bamboo or clay could demand more skill and sometimes cost more. Workshops facing deadlines therefore had strong reasons to choose faster materials.

Gopal explains the economic problem clearly: removing thermocol without receiving shola at the same price and speed means working slower for the same money. These materials became popular despite their environmental costs because artisans had to balance deadlines, prices, labour and family livelihoods.

Alternatives to thermocol include shola, jute, handmade paper pulp, bamboo and clay ornaments. Artisans can also use cloth, zari, natural clay and natural pigments. Earlier finishing methods used tamarind-seed gum, chalk powder and arrowroot starch to prepare colours.

These materials work through slower, more skill-dependent processes. Gopal says shola was beautiful but took time. The article also notes that jute, paper, bamboo and clay ornaments may require more time and skill, and sometimes cost more. Clay itself must dry in stages: entel mati takes three to four days, while bele mati takes another five or six.

Weather can extend drying, and cracks may need fresh mud for repairs. The challenge is economic as well as technical. Koushik wants less waste, but natural decoration must remain affordable and fit festival deadlines for families who depend on idol-making.

Biodegradable materials can be broken down by natural processes over time. Environmentally persistent materials resist breakdown and remain in surroundings for much longer. This distinction matters during idol immersion, because decorations may either become manageable natural debris or remain as floating and gathered waste.

The article gives a practical contrast. Thermocol and plastic decorations can persist in the environment, so civic workers must collect and dispose of them carefully. Neel found thermocol floating on the Hooghly, plastic decorations gathering along ghats and coloured residue near the banks. Clay, straw and shola are traditional materials used in the idols and decorations.

The article does not provide exact decomposition times or detailed chemical evidence. Generally, natural plant-based materials and clay break down or disperse more readily than synthetic foam and plastic, though conditions vary. Koushik’s material choices aim to reduce persistent waste after immersion.