By Oliver Charles Harry - founder and creative director of Ghini Como, a mulberry silk scarf brand specialising in 100% zero-mile products based in Argegno on Lake Como
Quick facts: mulberry silk
- Mulberry silk is produced exclusively by Bombyx mori, a domesticated silkworm that feeds only on the leaves of the white mulberry tree (Morus alba) and cannot survive in the wild.
- Each Bombyx mori cocoon yields a single continuous filament averaging 600-900 metres in length, with some cocoons producing filaments of up to 1,500 metres.
- The fibroin protein that forms the structural core of mulberry silk contains approximately 45% glycine by amino acid composition - a higher proportion than any other silk-producing species - which is directly responsible for its crystalline structure, tensile strength and characteristic smooth surface.
- Sericulture, the cultivation of silkworms for silk production, has been documented in China since approximately 2700 BCE, with the earliest known silk fabric dated by archaeological evidence to around 3630 BCE.
- Mulberry silk accounts for approximately 90% of commercial silk production worldwide, with China producing between 53,000 and 60,000 metric tonnes of raw silk annually, followed by India at approximately 34,000 metric tonnes.
- The global silk market is valued at approximately USD 23 billion in 2026, with the luxury segment - the principal market for woven mulberry silk in scarves and accessories - posting consistent annual growth.
- Fibroin comprises 75-80% of the total protein content of silk fibre; the remaining 20-25% is sericin, a water-soluble gum protein that binds the filaments together in the cocoon and is largely removed during degumming before weaving.
What is mulberry silk? The ultimate guide to the world's finest natural fibre
Learning the various types of silk fibre can be daunting at first. When I first began learning about Lake Como's rich silk history when researching scarf production for Ghini, I know I felt rather overwhelmed by the different silk terms being bandied around.
While the complexities of every silk fibre is a subject too vast for one article, we can certainly focus on arguably the greatest of them all - mulberry.
Mulberry silk is not only the most sought after material for silk scarves but the most commercially significant and technically refined of all natural textile fibres.
It is produced through a specific biological process involving a single domesticated species - Bombyx mori - and its designation as the finest silk available to buyers is not a marketing position but a measurable consequence of the chemistry, uniformity and length of the fibre it produces.
Understanding what mulberry silk actually is requires understanding that process from its biological origins through to the finished woven fabric, and understanding why the specific properties of Bombyx mori silk are different in kind, and not merely in degree, from those of other silk varieties and from synthetic alternatives.
The origins of mulberry silk: Bombyx mori and the biology of sericulture
Bombyx mori - the domestic silk moth - is the biological foundation of all mulberry silk production.
It is, in the precise sense of the word, a domesticated species: it has been selectively bred by humans over approximately five millennia to such a degree that it can no longer survive without human intervention.
It cannot fly, it cannot find its own food, and its entire biological existence is oriented toward producing the cocoon from which silk is extracted.
The domestic silk moth was domesticated from the wild silk moth Bombyx mandarina, which has a range from northern India to northern China, Korea, Japan, and the far eastern regions of Russia.
The domestication process began during the Neolithic period, with historical records including Confucian texts suggesting that the use of Bombyx mori cocoons for silk production dates back to approximately 2700 BCE in China, with archaeological evidence indicating a possible earlier origin during the Yangshao period, and the earliest known silk fabric dated to 3630 BCE.
The term "mulberry silk" derives directly from the diet of Bombyx mori. Bombyx mori is what biologists call a monophagous species - it feeds exclusively on mulberry leaves, and the nutritional composition of mulberry leaves directly affects the texture and strength of the silk fibres the worm produces, making leaf quality a science in itself.
This inseparability of silkworm cultivation (sericulture) from mulberry cultivation (moriculture) is why the two practices have always developed in parallel, and why regions with optimal conditions for growing white mulberry trees have historically been the regions where the finest silk has been produced.
The silkworm caterpillar builds its cocoon by producing and surrounding itself with a long, continuous fibre.
Liquid secretions from two large glands within the insect emerge from the spinneret - a single exit tube in the head - hardening upon exposure to air and forming twin filaments composed of fibroin, a protein material. A second pair of glands secretes sericin, a gummy substance that cements the two filaments together.
Pupation occurs within a cocoon made of one continuous white or yellow strand of silk averaging about 915 metres long.
This filament is preserved intact for commercial use by killing the pupa with hot air or steam. The killing of the pupa before emergence is necessary because an emerging moth would break the continuous filament, rendering it impossible to reel as a single unbroken thread.
This is the biological fact at the centre of most ethical critiques of conventional sericulture, and it is the reason why so-called peace silk or ahimsa silk - in which moths are allowed to emerge before the cocoon is harvested - produces a shorter, less uniform fibre, because the moth's emergence necessarily disrupts the continuity of the filament.
The chemistry of mulberry silk: why fibroin and glycine content matter
The properties that make mulberry silk superior to other silk varieties - and categorically different from synthetic fibres - are rooted in its protein chemistry, specifically in the amino acid composition of the fibroin that forms the structural core of the fibre.
Fibroin is the main protein component of silk fibres, accounting for 75-80% of the total protein content.
It is responsible for silk's strength and resilience, ensuring the fabric's durability and tensile strength. Fibroin molecules are arranged in a distinct crystalline structure, which gives silk its smooth and lustrous appearance.
What distinguishes Bombyx mori fibroin from that of wild silk species is its specific amino acid composition. Bombyx mori contains a markedly higher proportion of glycine - around 45% - compared with all non-domesticated species, which contributes to the crystallinity and tensile strength of mulberry silk.
In contrast, wild silks such as those of Antheraea yamamai, Antheraea pernyi and Attacus atlas have higher alanine levels, between 39% and 47%, which is associated with greater fibre stiffness and brittleness.
This higher glycine content is the structural reason why mulberry silk feels smoother against the skin than wild silk varieties, why it produces a more even, prismatic sheen when woven, and why it has a greater capacity for fine printing and dyeing - the fibre's uniform crystalline surface accepts dye molecules with a consistency that coarser, less uniform fibres cannot match.
Sericin (the fibroin fibres' sticky protein coating) helps to bind the silk fibres together by serving as a protective layer for the silkworm during the cocooning process.
To prepare silk for commercial use, sericin is usually eliminated during the degumming procedure, though minute amounts might still be present in mulberry silk, adding to its inherent ability to wick away moisture and hypoallergenic qualities.
Mulberry silk versus other silk varieties: what actually separates them
The term "silk" covers several distinct fibre types produced by different species, and the differences between them are significant enough to matter to anyone making a purchasing decision.
Tussah silk (also called tasar or wild silk) is produced by Antheraea species that feed on oak, juniper, and other leaves in semi-wild conditions.
The cocoons are less uniform than those of Bombyx mori, the filaments are shorter and more irregular, and the finished fabric is coarser, darker in its natural colour, and more variable in surface texture.
Tussah silk cannot be bleached to white without compromising the fibre, which limits the colour range available for printing and dyeing. It has its own market and aesthetic value, but it is a categorically different product from mulberry silk.
Eri silk is produced by Samia ricini, a species that feeds on castor leaves and is notable for producing an open-ended cocoon that allows the moth to emerge naturally - making it suitable for the ahimsa silk market.
The resulting fibre is short-staple rather than continuous-filament, giving it a matte, cotton-like appearance and feel that is entirely unlike the characteristic sheen of mulberry silk.
Muga silk is produced exclusively in Assam, India, by Antheraea assamensis, and is characterised by a natural golden colour that intensifies with washing over time. It is an extremely specialised product used primarily in traditional and ceremonial textiles, with negligible presence in the international luxury market.
The relevant comparison for anyone buying a mulberry silk scarf is between mulberry silk and synthetic alternatives - polyester, viscose, and nylon - which are regularly sold under descriptions that imply silk-like properties.
The fundamental difference is chemical: mulberry silk is a protein fibre with a structure similar to human hair, while synthetics are polymer chains with entirely different thermal, mechanical, and surface properties that produce measurably different results in how the fabric feels against skin, how it holds colour, and how it responds to wear.
The physical properties of mulberry silk: what the science confirms
The properties most frequently attributed to mulberry silk - its warmth against skin, its thermoregulatory character, its hypoallergenic quality and its sheen - are each the measurable result of the fibre's physical and chemical structure, rather than mere marketing hyperbole.
Thermoregulation: Silk's thermoregulatory properties derive from the protein structure of fibroin, which responds to changes in ambient temperature and humidity differently from polymer fibres.
Unlike synthetic fabrics, silk is naturally breathable and adjusts to body temperature - this thermoregulation prevents excessive sweating, keeps the wearer cool in summer and warm in winter, and by reducing moisture accumulation, minimises the growth of allergens.
Hypoallergenic properties: Mulberry silk is naturally hypoallergenic, making it ideal for people with sensitive skin or allergies, as it resists dust mites, molds and fungi.
This resistance is a consequence of the fibre's protein composition and its low moisture retention relative to cotton and wool - environments that dust mites require to colonise a textile are not present in well-maintained silk at the same level as in natural cellulosic or heavily absorbent fibres.
Sheen and light refraction: The characteristic lustre of mulberry silk results from the triangular cross-section of the fibroin filament, which refracts light at multiple angles simultaneously, producing the shifting, prismatic quality that is visible when the fabric moves.
This is distinct from the flat, directional reflection of polyester satin, which reflects light from a single angle consistently and produces a brighter but less complex sheen.
Tensile strength: Mulberry silk fibres are incredibly strong and durable, often being compared to steel in terms of tensile strength - a comparison that refers specifically to the tensile strength-to-diameter ratio of the individual filament, rather than to absolute load-bearing capacity.
At the same diameter, a mulberry silk filament is stronger than a steel wire of equivalent dimension. This property, combined with the natural elasticity of the protein structure, is why well-maintained silk garments can remain in active use for decades without degrading in the way that synthetic alternatives do.
How mulberry silk is graded: understanding quality before you buy
Not all mulberry silk is equivalent in quality, and the grading system used in international trade provides a meaningful guide to what buyers are actually purchasing.
Raw silk is graded according to China's GBT 1797-2008 Raw Silk Quality Standards, with grades running from 6A (highest) through 5A, 4A, 3A, 2A, A, B, C, and lower.
Grade 6A silk represents long, unbroken filaments with uniform diameter, high lustre, and minimal impurities - the grade used by luxury producers for fine scarves and accessories.
Lower grades contain shorter or less uniform filaments, more variation in fibre diameter, and a corresponding reduction in the smoothness and sheen of the finished fabric.
Momme weight (the Japanese unit of measurement that has become the industry standard for expressing silk fabric density) is the other critical quality indicator. One momme equals 3.75 grams, and for a scarf the relevant momme weight indicates how much silk is contained per unit of fabric area.
At 12–14 momme, the fabric has sufficient density for the colour in a printed design to read cleanly, for the drape and handle to express the characteristics of silk properly, and for the fabric to withstand the handling that a worn scarf receives without degrading.
Below 10 momme, the fabric is so light that its structural integrity is compromised in practical use. Above 18 momme - the weight at which Hermès produces their classic carré scarves - the additional density produces a handle and longevity that are measurably different from lighter weights, though at a price point that reflects the proportionally greater quantity of silk used.
Mulberry silk and Como: why the combination matters
Mulberry silk as a raw material reaches its fullest expression as a finished fabric when it is processed by workshops with the printing and finishing expertise necessary to realise the potential of the fibre.
The Province of Como in northern Italy has been Europe's centre of luxury silk weaving, printing, and finishing for over 600 years, and the concentration of technical knowledge in the district - in colour chemistry, screen printing precision, degumming, and hand finishing - is the reason why mulberry silk processed in Como has a character distinct from the same fibre processed elsewhere.
The fibre and the craftsmanship are inseparable in the finished product. Mulberry silk provides the uniform, long-filament raw material that accepts dye molecules consistently across a complex print.
The Como workshop provides the printing expertise to exploit that consistency with the precision that luxury buyers require. Neither is sufficient without the other, and the combination of Grade A or above mulberry silk fibre with Como's printing and finishing expertise is what defines the specific quality of a Como mulberry silk scarf.
Oliver Charles Harry is the founder of Ghini Como, a luxury silk scarf brand based on Lake Como. He lives in Argegno on the western shore of Lake Como.
