What Is Silk Fabric? Fibre, Weave and the 18 Families Explained
Silk is the only natural filament fibre — a continuous protein thread reeled from a cocoon and woven into cloth. Almost every trade name you will meet is a weave plus a finish, and knowing which is which is the whole of buying silk.
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What silk fabric actually is
Silk is a protein fibre spun by the larva of the mulberry silkworm (Bombyx mori) to build its cocoon. One cocoon yields a single continuous filament that can be several hundred metres long; reeled together, those filaments become the yarn that is woven into silk fabric. That continuity is what separates silk from every spun fibre: there is no short-staple twist, so the cloth can be both extremely fine and extremely strong.
So yes — silk is a fabric, a textile, a natural fibre and a woven material, all at once. The distinctions people actually argue about are elsewhere: whether the cloth in front of them is mulberry silk or a polyester imitation, whether it is reeled filament silk or spun from short fibres (noil, spun silk), and what weight it is. Those three questions decide the price far more than the word "silk" does.
How silk fabric is made
The sequence matters because each step explains a property you can feel.
- Sericulture. Silkworms are raised on mulberry leaves for roughly 25–28 days, then spin a cocoon over about three days.
- Stifling and reeling. Cocoons are heated to stop the moth emerging, then the filament is unwound and reeled — several filaments together form one yarn. Double cocoons, where two worms spin together, cannot be reeled evenly and become the slubby yarn used in dupioni and shantung.
- Degumming. Raw silk carries sericin, a gum that makes it stiff. Boiling it off leaves the soft, lustrous fibre most people recognise as silk.
- Twisting and weaving. Yarns are twisted (plain, or alternating S and Z for crepe), then woven: plain weave for habotai and organza, satin weave for charmeuse and duchess, twill for foulard, jacquard for brocade.
- Dyeing and finishing. Piece dyeing with reactive dyes, digital or screen printing, then washing, calendering or sandwashing depending on the hand required.
The weave, not the fibre, makes the fabric. Charmeuse and habotai can come from the same yarn; one is a liquid satin, the other a light plain weave. When a buyer says "I want silk", the useful next question is "which weave, at what weight".
Properties buyers rely on
| Property | What it means in practice |
|---|---|
| Breathable and thermoregulating | Warm in winter, cool in summer, and it does not trap heat the way polyester satin does. |
| Strong but not abrasion-proof | The filament is strong in tension; the surface still marks and abrades at collar edges and cuffs. |
| Low elasticity | Silk stretches only 15–20% before breaking and recovers poorly, which is why close-fitting styles use a stretch charmeuse (2–6% elastane) rather than bias alone. |
| Shrinks 3–5% on first wash | Always pre-shrink before cutting a production run, or specify a sanforised finish. |
| Dyes deeply, fades in sun | Reactive dye gives rich, even colour; UV will still take it out of an unlined curtain within a season. |
| Absorbs moisture without feeling wet | The reason silk is used for sleepwear and linings against the skin. |
The 18 families, in plain language
Almost every silk trade name is a weave plus a finish. Grouped by hand:
- Satin face, liquid drape: charmeuse, crepe-back satin, duchess satin, mikado (matte), peau de soie.
- Matte and crease-resistant: crepe de chine, georgette, crepe marocain, zibelline, sandwashed silk.
- Sheer and crisp: organza, gazar, silk tulle, gauze, marquisette.
- Sheer and soft: chiffon, voile, batiste.
- Plain and practical: habotai (China silk), pongee, broadcloth.
- Textured: dupioni, shantung, noil, tussah, matka, raw silk.
- Pattern in the cloth: jacquard, brocade, damask, moiré, matelassé, velvet, lamé.
- Print and colour base: twill, foulard, digital printed silk.
Each family has a page on this site with its weights, weights table and photographs — start at the fabric library. If you are choosing your first silk, read the beginner note below rather than the full list.
If you have never bought silk before: start with 16 mm crepe de chine. It is opaque enough to be a garment, matte enough to hide sewing mistakes, and stable enough that it will not fight you on the machine. Everything else can follow once you know what 16 mm feels like.
Grade, momme and what the label hides
Grade describes the raw yarn: 6A is the top of the Chinese scale for evenness, cleanliness and reelability. Momme describes the finished cloth: weight per 3.75 grams per square yard, or about 4.31 gsm per momme. They are independent. A 6A yarn can be woven at 6 mm, and a 19 mm satin can be woven from ordinary yarn.
Two things a label usually hides: the momme tolerance (a "16 momme" cloth may legitimately be 14.5) and the fibre content of trims, linings and anything described as "silk-touch". Ask for both in writing. For weight-by-weight detail, see the momme chart.
IM Silk is the export brand of Predatex Silk Co., Ltd., a mulberry silk weaver and dyer in Wuhu, Anhui, China. Browse the fabric library or request a swatch card.
Frequently Asked Questions
Is silk a fabric or a fibre?
Both. Silk is the protein fibre produced by the silkworm, and "silk fabric" is the cloth woven from it. The word covers a family of weaves — charmeuse, crepe de chine, organza and so on — that behave very differently at the same weight.
Is silk a natural fibre?
Yes. Silk is a natural protein fibre secreted by the mulberry silkworm, unlike polyester or nylon which are synthetic polymers. Silk is the only natural filament fibre produced in long continuous lengths.
What are the different types of silk fabric?
Eighteen families cover most of the trade: satin weaves (charmeuse, duchess, mikado), crepes (crepe de chine, georgette), sheers (organza, chiffon, tulle, gauze), plain weaves (habotai, pongee), textured weaves (dupioni, shantung, noil) and patterned weaves (jacquard, brocade, velvet).
Is silk fabric sustainable?
It is renewable and biodegradable, and mulberry trees support a low-input agricultural system, but it is resource-intensive per kilogram and conventional degumming uses significant water and energy. Treat it as a durable, repairable fibre rather than an automatically green one.
What is 6A grade mulberry silk?
6A is the highest grade in the Chinese raw-silk classification, scored on filament evenness, cleanliness and reelability. It grades the yarn before weaving, not the finished cloth, so it should be quoted alongside momme rather than instead of it.
What is the softest silk fabric?
For touch against skin, 6 mm chiffon and 5 mm habotai are the softest, followed by sandwashed charmeuse. Softness comes from weight and finish as much as from the fibre.
Swatches, Weights and Wholesale Pricing
We weave 18 families of 100% mulberry silk from 3 to 70 momme, in 114 cm and 140 cm widths, with MOQ from 1 metre on stock colours. Order a swatch card, or send a garment spec and we will name the family and momme that fits it.
Email jasom@predatextile.com · WhatsApp / Skype: +86 182 9825 8162 · ready stock · wholesale