Experiments with natural dyes and coloured cocoons for Pashmina and silk

Conventional textile dyeing uses chemicals that produce wastewater that pollutes rivers and ecosystems.
Researchers in Kashmir are testing plant-based dyes for Pashmina and exploring in vivo silk colouring, where silkworms produce coloured silk through their diet.
Financial and policy support, colour shade standardisation, and greater awareness are needed to scale these products.

Colour is at the heart of Kashmir’s textile traditions, especially for the world renowned Pashmina shawls and Kashmir silks. Yet producing these rich hues often comes with an environmental cost to ecosystems.

Studies show that many textile industries use synthetic dyes during dyeing and printing processes. When wastewater from these processes is released without proper treatment, these chemicals can enter rivers and streams, polluting water and harming aquatic life. Globally, the textile industry is among the largest sources of water pollution, with the dyeing processes contributing significantly to chemical discharge.

Researchers in Kashmir are now exploring alternative ways to colour these fibres using plant-based natural dyes for pashmina and feeding pigment-infused diets to silkworms for them to spin naturally coloured silk. These approaches, they say, aim to reduce textile production’s contribution to pollution while maintaining the value of high-end natural fibres.

Traditional dyeing process for Pashmina textiles. Pashmina yarn is gently submerged and lifted from the dye vat, ensuring even absorption while maintaining low heat to preserve fiber quality. Image by Tayoor Ahmad. — Traditional dyeing process for Pashmina textiles. Pashmina yarn is gently submerged and lifted from the dye vat, ensuring even absorption while maintaining low heat to preserve fibre quality. Image by Tayoor Ahmad.

Plant-based natural dyes for Pashminas

Pashmina from the Ladakh region is considered one of the world’s most luxurious natural fibres. The woollen fibre comes from the undercoat of Changthangi goats raised in the extremely cold, high-altitude Changthang plateau of Ladakh at around 3,500-4,000 metres above sea level.

“The global reputation of Kashmiri Pashmina is also closely linked to the traditional craftsmanship of Kashmiri artisans,” Asif Hassan, a professor in the division of Livestock Products Technology, Sher-e-Kashmir University of Agricultural Science and Technology of Kashmir (SKUAST-K) says.

“Pashmina’s processing methods have historically relied on labour-intensive manual techniques such as dehairing, combing, hand spinning and hand weaving, carried out without machines or chemicals. These skills, passed down through generations, are central to the authenticity and value of genuine Pashmina products.”

Hassan’s research work focuses on eco-friendly dyeing, which involves the extraction of natural dyes from plant sources and their application on natural fibres such as Pashmina, wool, and silk. Chemicals are used in washing and dyeing, including non-ionic detergents, sodium carbonate, synthetic dyes such as acid dyes and metal-complex dyes, and mordants (a mordant is a substance used in dyeing that helps the dye attach firmly to the fibre and improves colour durability) like ferrous sulphate and copper sulphate. “Finishing treatments may also involve chemical softening agents to enhance the texture and appearance of the fabric,” Hassan says.

“Textile dyeing wastewater is one of the major sources of environmental pollution,” Hassan adds. In fragile Himalayan ecosystems, such pollution can severely impact freshwater systems that communities rely on for drinking water, agriculture and livelihoods.

Pashmina fabric dyed with natural plant extracts drying after the dyeing process. Image by Hirra Azmat.

A recent study conducted by Hassan and his colleagues identified plant species such as the Indian barberry (Berberis aristata) and red bistort (Bistorta amplexicaulis) as promising natural dye sources for Pashmina.

Published in the journal Coloration Technology in 2025, the study found that these plants can produce a range of shades— from golden hues to reddish and pinkish tones due to their natural pigments. “These dyes show strong affinity for protein-based fibres like Pashmina,” Hassan says. “The use of mordants helps improve dye uptake and enhances the depth and uniformity of colours. Alum was found to be a particularly effective mordant compared to chemical alternatives, making the dyeing process more environment -friendly.”

The results show that these natural dyes demonstrate good fastness properties, meaning the colours remain stable under light exposure, rubbing and washing. Researchers suggest that the use of locally available plant biodiversity could support sustainable livelihoods, by creating income opportunities for rural communities.

According to Aijaz Ahmad Shah, a Pashmina spinning trainer associated with SKUAST-Kashmir, natural dyes are biodegradable and do not produce toxic effluents. They are also gentle on delicate Pashmina fabric and help preserve its softness and fibre integrity.

Moreover, natural dyes have historically been used by artisans across India, including Kashmir, in the handloom and handicrafts sectors for centuries, Shah adds.

However, Hassan notes that further research is needed before these techniques can be adopted at an industrial scale. “Optimisation of extraction processes, dye concentration and mordanting protocols will be necessary to ensure consistency,” he says. “Standardisation of colour shades, fastness and cost-benefit analysis will also be required for widespread commercial adoption.”

He adds that environmental sustainability in the Pashmina sector requires improvements across the entire value chain — from goat rearing to processing and certification. “Better grazing management, nutrition, shelter, healthcare and scientific breeding of goats can improve production, while eco-friendly processing and reduced chemical use can lower environmental impact. Quality assurance technologies such as microscopy, DNA testing, colourimetry, geographical identification (GI) tagging and QR-code labelling are also helping verify authenticity and strengthen consumer trust,” says Hassan.

A pedal-operated charkha developed by researchers SKUAST-K helps artisans spin delicate pashmina fibre more efficiently. Image by Hirra Azmat. — A pedal-operated charkha developed by researchers SKUAST-K helps artisans spin delicate Pashmina fibre more efficiently. Image by Hirra Azmat.

Dietary supplement for silkworms to produce coloured cocoons

Researchers in Kashmir’s silk sector are experimenting with a more radical approach — eliminating the dyeing stage altogether.

While Pashmina remains a heritage fabric, silk produced in the Kashmir Himalaya is also distinctive. The region’s temperate climate influences mulberry (Morus alba) growth and silkworm physiology, resulting in high-quality bivoltine silk known for its long filament length, strength and natural lustre.

Kashmiri silk has historically been used in high-end garments, furnishings, and ceremonial textiles, linking the region to international textile and design industries. “However, conventional silk dyeing relies heavily on synthetic dyes such as acid dyes, reactive dyes, metal-complex dyes and azo dyes,” Firdose Ahmad Malik, an assistant professor and scientist at the College of Temperate Sericulture, SKUAST-Kashmir says. “Although these dyes produce bright and durable colours, they can generate chemical effluents and environmental pollution if not properly treated.”

Malik’s research focuses on improving silkworm nutrition, disease management and technologies to improve silk production in Kashmir. He and his team are now exploring in vivo silk colouration, where silkworms (Bombyx mori) produce coloured silk directly through dietary supplementation. He explains that this method represents a significant shift — from dyeing silk after production to generating colour during silk formation.

According to the research team, during the final larval stage, silkworms are fed a specially formulated diet containing selected pigment molecules. After ingestion, the pigments are absorbed into the silkworm’s digestive system and transported through the hemolymph — the insect’s circulatory fluid — to the silk glands. Inside these glands, the pigments interact with silk proteins such as fibroin and sericin. As the silkworm spins its cocoon, the pigments become integrated into the silk fibre, producing naturally-coloured cocoons.

Malik says this approach could significantly reduce effluents and pollution from the textile dyeing industry by reducing the need for dye baths, repeated washing cycles and chemical treatments.

The production of coloured silk through dye-infused diets in silkworms (Bombyx mori) is based on the biological ability of the larvae to absorb and transport certain pigment molecules from their food into the silk glands, where silk proteins are synthesized. Image by Hirra — The production of coloured silk through dye-infused diets in silkworms is based on the biological ability of the larvae to absorb and transport certain pigment molecules from their food into the silk glands, where silk proteins are synthesised. Image by Hirra Azmat.

The coloured cocoons could therefore lower water consumption, reduce chemical waste and improve energy efficiency in silk processing. Farmers could also benefit economically, as speciality-coloured cocoons may fetch higher prices in markets seeking textiles manufactured with less-polluting processes, he adds.

However, several challenges remain before the technology can be widely adopted. “Researchers must ensure uniform colour intensity, pigment stability during processing and consistent pigment absorption by silkworms. The cost and availability of pigments and the development of scalable feeding protocols also require further research.”

Besides, the scientists are also exploring other innovations to make sericulture more sustainable. These include developing disease-resistant silkworm breeds, using precision technologies such as sensors and artificial intelligence to optimise rearing conditions, and adopting renewable energy systems like solar-powered reeling machines.

“Circular practices are also being promoted, such as recycling silkworm waste into compost, animal feed or biomaterials,” Malik explains. “With continued research and collaboration between scientists and industry stakeholders, these innovations could strengthen sustainable sericulture while creating better economic opportunities for silk farmers.”

Slightly tinted silk threads from the in vivo colouration process. Researchers are working on intensifying the colours in the future experiments with increased dose and concentration. Image by Hirra Azmat. — The control group compared to the slightly tinted silk threads from the in vivo colouration process. Researchers are working on intensifying the colours in the future experiments with increased dose and concentration. Image by Hirra Azmat.

Market and industry perspectives

Pashmina traders say sustainability is also becoming important in the global market. Sheikh Adnan, founder of Srinagar-based store The Shawlwala, says producing a genuine Pashmina shawl is a time-intensive process that can take weeks or even months depending on the design. “The artisans are gradually experimenting with natural dyes and traditional processing methods,” he says. “While natural dyes can make colour consistency more difficult, the slight variations also make each piece unique.”

International buyers — particularly in Europe and the Middle East — show strong interest in sustainably-produced textiles, though younger Indian consumers are also increasingly valuing handmade and ethical products.

Riyaz Bhat, a Kashmiri rug trader based in Qatar, says, there is growing demand from international buyers for sustainably produced textiles, including Pashmina and silk.

“Natural dyes and green processes yield unique textures and colours that attract customers more than synthetic colours,” Bhat says. “Not only that, they also are much longer lasting than synthetic ones,” Bhat says.

However, shifting to sustainable practices presents challenges. “Eco-friendly methods take more time and can be expensive, while markets still expect reasonable prices,” Adnan says.

He believes sustainable production can strengthen the global value of Kashmiri crafts. “In the long run, sustainable practices can help preserve both the heritage of Kashmiri crafts and the livelihoods of the artisans who depend on them.”

Bhat explains, “Eco-friendly products are definitely at least 20-30% more expensive but worth it as they are more sustainable and long lasting with no synthetic materials or dyes used. Since it takes a lot more time to work on these products, the labour costs increase and prices go up.”

Hassan argues that it is not the methods that inherently increase costs, but factors such as limited availability of raw materials, lack of systematic cultivation, small-batch dye extraction, and labour-intensive traditional processing techniques, that may increase the overall cost by approximately 15–20% compared to synthetic dyeing methods.

While the in vivo silk colouration is in the research and development phase, Hassan adds that even Pashmina products with natural dyes remain a small niche segment and are not part of mainstream production.

Cocoons are collected, and the larva inside is stifled using hot air or steam to prevent the moth from breaking the silk filament. The cocoons are then sorted by size, colour, and texture. Image by Bilal Bahadur. — Cocoons are collected and sorted by size, colour, and texture. Image by Bilal Bahadur.

Steps for scaling up

Scaling up eco-friendly Pashmina production requires a multi-pronged approach, notes Hassan. “This includes developing a reliable raw material supply chain through the identification and systematic cultivation of suitable plant biodiversity for natural dyes. There is also a need for research and development (R&D) for technology standardisation in dye extraction and application to ensure consistency and scalability.”

While adding that financial incentives and policy support for eco-friendly processing would help, he points out that targeted support for artisan clusters adopting green technologies is essential.

“Additionally, assistance with certification mechanisms (such as organic, GI, and eco-labels), enhanced consumer awareness about authentic eco-friendly Pashmina, and strong branding and marketing strategies will play a crucial role in expanding this segment,” Hassan added.

Regarding the in vivo silk colouration, Malik says that researchers expect support in terms of funding, infrastructure, and policy backing to further develop and scale this eco-friendly dyeing approach. “This includes financial assistance for advanced trials, access to well-equipped laboratories, and collaboration with industry partners for commercialisation. Additionally, regulatory support and awareness initiatives are needed to promote adoption of this sustainable technology among stakeholders in the sericulture sector,” he concludes.

Banner image: A finely embroidered Pashmina shawl displayed at a craft store in Kashmir. Image by Hirra Azmat.