Eri silk

Overview

Production: about 7,900 tonnes of raw silk (Indian eri silk, about 19% of India's raw silk output, as reported in the 2025-26 annual report). Main producers: India (mainly Assam, Meghalaya and other northeastern states). [1]

Silk associated with eri silkworms, commonly prepared as spun staple rather than a continuous reeled filament.

Feel and behavior

Matte, soft and more wool-like than smooth reeled silk.

Where you find it

Shawls, spun yarn and woven cloth.

Source and geography

Eri silk is produced by the eri silkworm, Samia ricini (also cited as Samia cynthia ricini or Philosamia ricini), a saturniid moth that, unlike most wild silkmoths, is domesticated and reared indoors. Its principal food plant is castor (Ricinus communis), the host implicated in its domestication; research has also examined rearing on an ancestral host, Ailanthus (Indian tree of heaven), and on cassava leaves. Production is centered in northeastern India, where the Central Silk Board's muga and eri institutes are based in Assam and Meghalaya, and eri is also reared in Thailand and elsewhere.

Worth knowing

• Eri makes up roughly a fifth of India's raw silk output, making it the country's largest non-mulberry silk.
• Meghalaya's Ryndia eri textile received a geographical indication tag in 2025, following recognition of Umden-Diwon as the state's first eri silk village in 2021.
• Because eri cocoons cannot be reeled, the moth's emergence does not destroy the commercial value of the silk, unlike most mulberry silk.

Types, grades and fabrics

Types and grades

Eri silk, called endi or errandi in Assam, comes from the domesticated eri silkworm, Samia ricini. Cocoons are mainly white, with a red or brick-colored strain. Because the cocoon is open-ended, eri is not reeled but spun, and trade forms include degummed fiber or tops, hand-spun yarn, mill-spun yarn in counts suitable for weaving and knitting, and noil from short waste. Hand-spun yarn is thicker and more irregular; mill-spun is finer and even. Eri is often sold as peace or ahimsa silk when moths emerge before processing. India's Ministry of Textiles reports eri at roughly 7,900 tonnes, about 19 percent of the country's raw silk output, in its 2025-26 annual report.

Fabrics and products

Eri is woven into shawls, stoles, chadars, blankets and jacket fabric in Assam and Meghalaya, and increasingly into scarves, suiting and knitting yarn for export. Meghalaya's Ryndia, a hand-spun, handwoven and often naturally dyed eri textile made by Khasi, Bhoi and Jaintia communities, received a geographical indication tag in 2025. Eri blends with cotton, wool or mulberry silk appear in stoles and suiting. Its matte, woolly texture suits winter wraps rather than lustrous evening wear.

Buying and care

How to judge quality

Genuine eri has a matte, slightly textured surface, a soft, warm hand and a mild natural sheen, unlike the glassy luster of reeled mulberry silk. Hand-spun cloth shows slubs and slight irregularity, which is expected; very uniform cloth may be mill-spun or a blend. Check the fiber label for 100 percent silk or for blend percentages, and look for the Silk Mark label on Indian products, which certifies pure natural silk. For Ryndia, look for authorized GI users. Peace silk claims should be backed by the producer's description of how cocoons were handled.

Care in detail

Hand wash in cool water with a mild, pH-neutral silk or wool detergent, or dry clean if the label requires it, especially for naturally dyed pieces that may bleed. Do not soak for long, wring or rub. Roll in a towel to remove water and dry flat or on a padded hanger in shade, since sunlight yellows and weakens silk. Iron on a low silk setting on the reverse while slightly damp, or steam. Spot clean with cold water; avoid chlorine bleach and enzyme detergents. Store folded with acid-free tissue in breathable cloth and check for carpet beetles. The product label governs.

Care at a glance

Follow the complete product’s care label. Blends, dyes, finishes and construction can change suitable washing, drying and storage.

Environmental and social footprint

Eri is reared indoors on castor or other host leaves, commonly as a small household activity in Assam and Meghalaya, and castor is also grown for oil, so land use is partly shared. Because cocoons are spun, moths can be allowed to emerge; pupae are also eaten locally, which matters for how ethical claims are framed. No peer-reviewed life cycle assessment of eri fabric was found in this review. Degumming uses soap or alkali and heat, and natural dyeing can use mordants with their own effluent concerns. Hand spinning and weaving provide rural income, but wages and conditions vary and are rarely documented.

Tradeoffs

Origin, processing inputs, labor, product construction and useful lifetime all need specific evidence. The name alone does not establish responsible production.

A useful question to ask: What exact material, product form and documented producer stand behind this name?

Science

Protein: fibroin

Silkworms form a protein filament. Reeling, spinning and degumming change its textile form.

Structure and chemistry

Eri silk consists of fibroin filaments coated in sericin. Saturniid fibroins differ from Bombyx mori fibroin: their crystalline regions are built largely from polyalanine runs rather than the glycine-alanine repeats of mulberry silk, and eri fibroin contains the arginine-glycine-aspartic acid (RGD) cell-binding tripeptide. Comparative synchrotron FTIR, X-ray diffraction and Raman studies (Fang et al., 2016) found eri and other non-mulberry silks more extensible than mulberry silk, with properties tied to beta-sheet content, crystallinity and molecular orientation. Most cocoons are white, but some strains are red because they accumulate 3-hydroxyanthranilic acid, a tryptophan metabolite.

From source to yarn

Larvae are fed cut castor leaves indoors. The eri cocoon is loosely built and open at one end, so its filament cannot be reeled like mulberry silk; instead cocoons, often after the moth has emerged, are degummed in soap or alkaline solutions to remove sericin, then opened and spun as a staple fiber, by hand in village production or on spun-silk machinery. Pupae are an edible by-product in parts of northeastern India, which matters for ethical claims. Eri fibroin is also hard to dissolve, which has limited its use as a regenerated biomaterial compared with mulberry fibroin.

Performance in use

Spun eri yarn has a matte, cotton- or wool-like appearance and a soft, warm hand because the staple structure traps air, unlike the smooth luster of reeled mulberry silk. Its higher extensibility contributes to toughness. As a protein fiber, eri absorbs moisture, chars rather than melts, and takes acid and natural dyes, although its uptake can differ from mulberry silk. It is weakened by strong alkali, chlorine bleach and prolonged sunlight, and stored cloth can be damaged by carpet beetles and other textile pests.

How it is identified

Burn tests (indicative only; use care) show silk behavior: burning with a hair-like odor and leaving a crushable ash. Saturniid silk filaments are generally flatter and wider in cross-section than Bombyx mori filaments, and FTIR or Raman spectra reflect their alanine-rich crystalline domains. Handloom eri may be confused with tussar or with spun mulberry silk waste, and blends with cotton are common, so fiber-content testing is advisable before relying on a claim of pure eri.

History

Timeline

1. 2016A comparison of commercial silks found eri and other non-mulberry fibers more extensible than Bombyx mori silk, tied to beta-sheet content and orientation. [3]
2. 2021Umden-Diwon was recognized as Meghalaya's first eri silk village. [2]
3. 2023Work on the castor silkworm examined its dietary adaptations when transferred to an ancestral host plant. [5]
4. 2025Meghalaya's hand-spun, handwoven Ryndia eri textile received a geographical indication tag. [2]
5. 2026A horizontally acquired gene was shown to mediate red cocoon pigmentation in the eri silkmoth. [4]

Eri silk is closely linked with northeastern Indian textile traditions. Ethical claims about harvesting must be verified for the actual process and cannot be inferred from the fiber name alone.

The deeper record

Eri culture is a long-standing household activity in northeastern India, and its domestication on castor sets it apart from the wild saturniid silks. India's Central Silk Board supports eri through the Central Muga Eri Research and Training Institute in Jorhat and the Muga Eri Silkworm Seed Organization in Guwahati. Research has broadened eri rearing to castor grown on wastelands and to alternative hosts such as cassava in Thailand, and a 2026 study warned that heavy metals from contaminated sites can accumulate in edible eri pupae even when the silk itself contains little.

Labeling and law

In both the US and the EU the generic fiber name is silk, and eri is a descriptive qualifier. Regulation (EU) No 1007/2011 defines silk as fiber obtained exclusively from silk-secreting insects. Terms such as peace silk or ahimsa silk, often applied to eri, are voluntary ethical claims with no legal definition; they are meaningful only if the producer documents that moths emerged before processing and states what happened to the pupae. One research group describes eri production as not sacrificing moths, but that describes a practice, not a property of the species.

This describes what rules and standards cover. It is not legal advice; jurisdiction, product form and current rule text control.

Frequently asked

Is eri silk really cruelty-free?

Eri cocoons are open-ended, so the moth can emerge before the silk is processed, and much eri is produced this way. It is not guaranteed: some producers process cocoons with pupae inside, and pupae are eaten locally. Ask how the cocoons were handled.

Why doesn't eri silk look shiny?

Eri is spun from short degummed fibers rather than reeled as continuous filament. Spun yarn has fiber ends on its surface that scatter light, so eri looks matte and feels more like fine wool or cotton.

Is eri silk warm?

Yes. Spun eri traps air in its structure and is traditionally used for winter shawls and wraps in northeastern India. It is warmer than smooth reeled silk of the same weight.

What is Ryndia?

Ryndia is the Khasi term for a hand-spun, handwoven eri silk textile from Meghalaya, often naturally dyed. It received a geographical indication tag in 2025, which reserves the name for authorized producers from the region.

Sources

• Food and Agriculture Organization: Harvesting of textile animal fibres
• Journal of Materials Chemistry B: Structural-mechanical relationship in mulberry and non-mulberry silkworm silks (Fang et al., 2016)
• Frontiers in Insect Science: Dietary adaptations of the castor (eri) silkworm transferred to an ancestral host (2023)
• Zoological Research: A horizontally acquired gene mediates cocoon pigmentation in the eri silkmoth (2026)
• Environmental Research: Heavy metal pathways from soil to silkworm in wasteland-based eri farming (2026)
• Biomedical Materials: Nonmulberry silk proteins, multipurpose ingredient in bio-functional assembly (2021)
• Ministry of Textiles (India): Annual Report 2025-26
• The Shillong Times: Meghalaya's Ryndia silk gets GI tag (2025)
• Silk Mark Organisation of India: About SMOI
• UNI India: Meghalaya's Ryndia, eri silk textile accorded GI tag

Cite this page

Chaos. (2026). Eri silk. In Fibers of Earth: An independent textile atlas. https://www.hendrickresearch.com/fibers/materials/eri-silk/