Animal

Silk

Q: Is mulberry silk better than other silk?

Mulberry silk from domesticated Bombyx mori gives long, fine, even filaments that reel into smooth, uniform cloth, which is why it dominates charmeuse and crepe de chine. Wild silks such as tussah are coarser, textured and often golden or brown, valued for a different look rather than being worse in every use.

A continuous filament, a luminous cloth.

Reviewed 2026-09-22. Evidence level: verified. Open the interactive profile and route map.

Key figures

Cocoon composition: roughly 70 to 80% fibroin and 20 to 30% sericin
Cocoon filament length: typically about 700 to 1,500 m (Bombyx mori)
Brin width: about 5 to 10 microns, rounded triangular cross-section
Moisture regain: about 11% at standard conditions (65% RH, 20 C)
Wet strength: roughly 15 to 20% lower than dry

Approximate values under the stated conditions.

Overview

Protein filament formed by silkworms in cocoons. Cultivated mulberry silk is one important type.

Feel and behavior

Smooth with characteristic luster and fluid drape.

Where you find it

Scarves, dresses, ties, linings and decorative textiles.

Source and geography

Most commercial silk comes from the domesticated silkworm Bombyx mori, whose larvae feed on mulberry leaves. Non-mulberry silks come from other moths: tasar from Antheraea species such as A. mylitta and A. proylei, eri from the domesticated Samia ricini, and golden muga from Antheraea assamensis, which is endemic to Assam and confined largely to the Brahmaputra valley. China is by far the largest producer, followed by India, with smaller output from Uzbekistan, Vietnam, Thailand, Brazil and others according to International Sericultural Commission statistics.

Advantages

Fine continuous filaments make very light, sheer fabrics that are still strong for their weight.
The triangular filament cross-section gives a characteristic luster that dyes deepen.
Its smooth surface suits linings and garments that should slide easily.
Silk drapes fluidly in charmeuse and crepe and holds crisp shapes in organza and taffeta.

Drawbacks

Sunlight yellows and weakens it, which limits use in curtains without lining.
Wet silk is weaker, water can leave spots, and perspiration and deodorant stain it.
Smooth, light weaves snag and show seam slippage.
Conventional reeling kills the pupae, which matters to many buyers.
Metallic weighting can make old silk split and shatter.

Worth knowing

A 2014 life cycle assessment of Indian silk found higher impacts than for most other fibers, driven mainly by cocoon production rather than weaving.
In that study, electricity for drying cocoons and for irrigation was the largest source of non-renewable energy.
Silk noil is the short fiber combed out while making spun silk, so a nubby noil fabric is effectively made from what the smoother yarns left behind.

Types, grades and fabrics

Types and grades

Mulberry silk from Bombyx mori is the reference type; tussah (tasar), eri and muga are wild or semi-domesticated silks with coarser, often naturally tinted fibers. Trade forms include reeled filament, spun silk made from waste and pierced cocoons, and silk noil, the short fiber combed out during spun-silk processing, which gives nubby, matte cloth. Fabric weight is stated in momme, and one momme is about 4.34 grams per square meter. Retail suppliers typically list organza at roughly 4 to 6 momme, chiffon 6 to 8, habotai 5 to 12, crepe de chine 12 to 16 and charmeuse 12 to 30. Within one fabric type, a higher momme means denser, more opaque and generally more durable cloth.

Fabrics and products

Charmeuse is a satin weave with a lustrous face and dull back, used for slip dresses, blouses and pillowcases. Habotai is a smooth, light plain weave for linings, scarves and silk painting. Crepe de chine uses highly twisted yarns in a plain weave for a matte, finely pebbled, fluid cloth in blouses. Chiffon is sheer and soft, from high-twist yarns in an open weave, for overlays and scarves. Organza is sheer but crisp, for bridal wear and structured layers. Dupioni is woven from irregular thread reeled from double cocoons, giving crisp, slubbed cloth for formalwear and curtains. Noil makes casual, textured fabric. Silk also appears as taffeta, satin, velvet and knitted jersey.

Buying and care

How to judge quality

Compare momme within the same fabric type: a heavier charmeuse is more opaque and hard-wearing than a lighter one, and very light satin weaves snag and show seam slippage more easily. Real silk has a soft, shifting luster, while polyester satin often looks flat and glassy. Silk often rustles faintly when squeezed (scroop), though finishing affects it. Read the fiber line, not the fabric name: 'satin' and 'silky' describe a weave or feel, and 'art silk' historically meant rayon. Heavily weighted silk drapes richly but can split with age, so an unusually heavy, cheap taffeta deserves questions. Check that seams are generous and finished, because loose weaves fray. Claims such as 'peace silk' or '6A grade' need supplier evidence.

Care in detail

Many silks are labeled dry clean because dyes may bleed or the weave may shrink or pucker, and the label governs. Washable habotai, crepe de chine and charmeuse can often be hand washed in cool water with a mild, pH-neutral detergent free of enzymes and bleach, after testing colorfastness on a hidden seam. Do not soak long, rub or wring; press water out in a towel and dry flat or on a padded hanger, out of sun. Iron on the reverse while slightly damp at the low setting the label shows, usually one dot (ISO 3758 caps it at 110 C) or two dots (150 C), with a pressing cloth, since water drops can spot. Apply perfume and deodorant before dressing and let them dry. Store silk clean, away from light, in breathable cotton bags.

Care at a glance

Check the label before washing. Avoid wringing, harsh detergents and prolonged direct sun; test colorfastness.

Environmental and social footprint

The main life cycle assessment of silk, a 2014 study by Astudillo and colleagues using survey data from Karnataka, India, found higher impacts than for most other fibers across impact categories. Cocoon production, not weaving, dominated: mulberry leaves and wood burned in cocoon processing supplied most renewable energy, while electricity for cocoon drying and irrigation supplied most non-renewable energy, and actual farm practices used more inputs than official guidelines. Mulberry cultivation also requires land, water and fertilizer. Degumming discharges sericin, a protein-rich effluent that researchers now study as a recoverable byproduct. Conventional reeling stifles the pupae with heat, and alternatives sold as 'peace' or 'ahimsa' silk lack a legal definition. Data outside India are scarce, so broad fiber rankings for silk rest on limited evidence.

Tradeoffs

Sericulture, cocoon processing and finishing practices vary. Silk does not imply a single animal-welfare method.

A useful question to ask: Is the producer able to explain the silk type, cocoon process and dyeing location?

Science

Data sheet

Property	Value	Conditions	Source
Density	1.32 to 1.40 g/cm3	with sericin; about 1.30 to 1.38 after degumming	[2]
Moisture regain	about 11 %	standard conditions (65% RH, 20 C)	[3]
Tenacity	about 21 to 45 cN/tex	dry, converted from 2.4 to 5.1 g/den; wet strength roughly 15 to 20% lower	[3]
Cocoon protein composition	70 to 80 fibroin, 20 to 30 sericin %	Bombyx mori cocoon	[1]
Cocoon filament length	about 700 to 1,500 m	single Bombyx mori cocoon	[1]

Protein: fibroin

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

Structure and chemistry

A Bombyx mori cocoon is wound from one continuous filament, typically several hundred to about 1,500 m long. Each filament is two fibroin strands (brins) glued together by sericin; fibroin makes up roughly 70 to 80% of cocoon silk and sericin 20 to 30%. Fibroin is assembled from a heavy chain of about 350 kDa, a light chain of about 25 kDa and the P25 glycoprotein in roughly a 6:6:1 ratio. Repeats such as GAGAGS in the heavy chain pack into antiparallel beta-sheet crystallites set in less ordered regions. Degummed brins have a rounded triangular cross-section about 5 to 10 microns wide, which scatters light and gives silk its luster.

From source to yarn

Larvae spin cocoons at the end of the feeding period. In conventional reeling the pupae are killed by heat or steam (stifling) so the filament stays unbroken. Cocoons are cooked to soften sericin, and the filament ends of several cocoons are reeled together into raw silk, which is then twisted (thrown) into yarn. Degumming, usually by soap or alkali at elevated temperature, hydrolyzes and removes sericin, removing a corresponding share of weight and revealing luster. Waste and pierced cocoons, including eri cocoons left after the moth emerges, are degummed and spun as staple (spun silk).

Performance in use

Silk has a standard moisture regain of about 11%. Dry tenacity is typically cited at about 2.4 to 5.1 g/den, but wetting disrupts hydrogen bonding and strength falls by roughly 15 to 20%, so wet silk should not be wrung. Ultraviolet light breaks hydrogen bonds and then oxidizes and cleaves the polypeptide chains, causing yellowing and strength loss, so silk curtains and linings degrade in sun. Silk takes acid, metal-complex and reactive dyes well. Metallic weighting (historically tin salts) increases drape and weight but accelerates deterioration.

How it is identified

Burn tests are indicative only and should be done with care: silk burns slowly, smells like burning hair and leaves a crushable black bead. Microscopy shows smooth, scale-free filaments with a rounded triangular cross-section; raw silk shows paired brins in a sericin sheath, while wild silks are generally coarser and flatter than mulberry silk. Protein spectroscopy (FTIR) and mass-spectrometric proteomics of fibroin peptides can confirm silk, a method used to detect silk residues in archaeological burials.

History

Timeline

c. 6500 BCEFibroin peptides detected in soil from Jiahu tombs in Henan are presented as evidence of silk use about 8,500 years ago. [4]
mid-6th century CEAccording to Procopius, monks brought silkworms to Constantinople for Justinian I, founding a Byzantine silk industry. [5]
1960The FTC issued an interpretation requiring disclosure of metallically weighted silk and the share of weighting. [6]
1995The FTC repealed that weighted-silk interpretation at 16 CFR 14.4, effective 15 August 1995, leaving misrepresentation actionable under Section 5. [6]
2014A life cycle assessment of Indian silk found cocoon production, not weaving, dominated impacts. [7]

Silk production has a long history in China and later spread through interconnected Asian, Middle Eastern and European textile cultures. Trade carried both cloth and design ideas. Modern sericulture and weaving still encompass many distinct traditions.

The deeper record

Mass-spectrometric detection of fibroin peptides in soil from tombs at Jiahu, Henan, published in PLOS One in 2016, is presented as biomolecular evidence of silk use about 8,500 years ago. The earliest known silk fabric fragments, more than 4,700 years old, come from Qianshanyang in Zhejiang, a Liangzhu culture site. According to Procopius, monks returning from the east brought silkworms to Constantinople for the emperor Justinian I in the mid-sixth century CE, founding a Byzantine silk industry that dominated European production for centuries.

Labeling and law

In the US, silk is a natural fiber name under the Textile Fiber Products Identification Act (15 U.S.C. 70 et seq.) and 16 CFR Part 303. The FTC's 1960 interpretation requiring disclosure of metallically weighted silk (16 CFR 14.4) was repealed effective August 15, 1995; the Commission said misrepresentation remained actionable under Section 5 of the FTC Act. In the EU, silk is an Annex I fiber name in Regulation 1007/2011. Terms like 'peace silk' or 'ahimsa silk' have no statutory definition and need supplier evidence.

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

Frequently asked

What is momme in silk?

Momme is a unit of silk fabric weight; one momme equals about 4.34 grams per square meter, so a 19 momme charmeuse weighs about 82 grams per square meter. Compare momme only within one fabric type, because a crisp organza and a fluid charmeuse behave very differently.

Is mulberry silk better than other silk?

Mulberry silk from domesticated Bombyx mori gives long, fine, even filaments that reel into smooth, uniform cloth, which is why it dominates charmeuse and crepe de chine. Wild silks such as tussah are coarser, textured and often golden or brown, valued for a different look rather than being worse in every use.

Can I wash silk in a washing machine?

Only when the label allows it. Some washable silks tolerate a cold delicate cycle in a mesh bag with mild detergent, but agitation can chafe the surface, fade color and leave a dull, whitish look. Hand washing is gentler, and dry cleaning is safer for structured, weighted or poorly dyed pieces.

Why is my white silk turning yellow?

Ultraviolet light and oxidation break down the fibroin protein, and residues of perspiration, deodorant or perfume speed the process. Chlorine bleach makes it worse. Wash out body soils promptly, store silk in the dark, and line silk curtains that face strong sun.

Sources

Cite this page

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