Where does silk come from?

In 2024 India produced 260,000 tonnes, 56% of the world's 464,010 tonnes (FAOSTAT). China followed with 32%, then Uzbekistan (6.5%), Vietnam (3.4%) and North Korea (0.6%). The top five account for 98%, 22 countries reported output and 0.3% came from outside the top ten. World production changed -34% over the ten years to 2024 and +1% on the previous year.

These figures count silkworm cocoons suitable for reeling, not finished silk thread, and the difference is large: roughly six to eight kilograms of fresh cocoons yield a kilogram of reeled raw silk. Few countries appear at all, because sericulture needs mulberry, a warm season and patient household labor in the same place.

That labor is the whole story. A crop of worms takes about a month from hatching to cocoon and has to be fed fresh chopped leaves several times a day, so rearing has stayed with smallholders even as the rest of the textile chain industrialized, and it retreats wherever rural wages rise.

China was the largest exporter of silk (HS 5002) in 2024 with 48% of world export value, ahead of Vietnam (25%), on world trade of $369.6 million (CEPII BACI). India was the largest importer with 32%.

The production and export tables disagree on purpose. Cocoons are grown in one set of countries and reeled into raw silk in another, and China reels the fine, even grades that high-end weaving demands. India is the largest cocoon producer and the largest buyer of raw silk at once, because its weaving and handloom sector consumes more thread than its filatures produce.

By value this is one of the smallest trades covered on this site, and it is a trade in an intermediate good: Italy imports raw silk to weave and exports fabric worth many times the thread, so the money in silk sits well downstream of the farm.

There is no futures market in silk and no free public benchmark price carried on this site, so none is quoted here. Cocoons are sold at government-supervised or cooperative auction markets in the producing districts, where the bid depends on the yield of dry cocoon and reelable filament rather than green weight. Raw silk is then sold by reelers on contract, priced per kilogram against grade and denier.

Grade does most of the work in the price. Raw silk is classified for evenness, cleanness and strength, and only the higher grades reel from bivoltine cocoons suited to power looms; coarser multivoltine silk sells at a discount into handloom and furnishing use. The visible references are auction results in India, Chinese export quotations and private assessments, and Chinese domestic policy has repeatedly set the tone for all of them.

Silk is the most labor-intensive fiber in commercial use, from leaf picking through rearing to reeling. When rural wages rise or workers move to cities, farmers stop rearing regardless of the silk price, which is why output has trended down in every country that has industrialized.

Pébrine and flacherie can wipe out a rearing, and because eggs come from specialist producers, a contaminated batch spreads the loss across many households at once. Egg quality control is the difference between a crop and a season wasted.

Bivoltine worms produce longer, more even filament that reels to the top grades, but they are harder to rear in hot weather. Multivoltine stock is robust and yields coarser silk, so the mix a country rears sets the grades it can sell and the prices it can reach.

Polyester and viscose filament imitate silk's drape at a fraction of the cost, so silk no longer competes on performance for most uses. Demand now rests on the fiber's identity in luxury clothing and furnishing, which makes it sensitive to fashion and to discretionary spending.

Leaf supply sets how many worms can be reared. Drought, frost or disease in the mulberry stands caps rearings months before any cocoon reaches market, and mulberry is a perennial, so a lost plantation is not replaced within a season.

Eggs are produced by specialist grainages and hatched to order. The larvae are fed chopped mulberry leaves through five growth stages over about a month, then mount frames and spin a cocoon from a single continuous filament, extruded as liquid protein and bonded by sericin, the gum that sets the shape.

Cocoons are then stifled with hot air or steam to kill the pupa, because a moth that emerges cuts the filament and leaves nothing to reel. Dried cocoons store for months. At the filature they are soaked in hot water to soften the sericin, the filament ends are found, and several filaments are combined with a slight twist into one reelable strand of raw silk, which is skeined and graded.

Raw silk is then thrown into yarn, degummed, dyed and woven. Pierced cocoons, outer floss and reeling waste are carded and spun into noil and spun silk, which are shorter-fibered and cheaper.

Almost all silk goes into textiles: saris, scarves, ties, shirting, lining and dress fabric, plus furnishings such as upholstery and rugs. It holds dye brilliantly and is strong for its weight, and those properties, rather than any technical necessity, keep it in production against far cheaper synthetics. Surgical sutures are one of the few remaining technical uses.

Pupae left after reeling are eaten in several countries and otherwise pressed for oil or milled into animal feed; sericin recovered from degumming goes into cosmetics; waste fiber becomes spun silk. Mulberry itself yields fruit, fodder and wood, and silk protein is now drawn on for medical and biomaterial research.

The chain begins in households and ends in luxury retail, which is an unusual span for any commodity. Egg producers supply rearers, rearers sell cocoons at local markets, filatures reel, weavers convert, and the cloth sells for thousands of times the value of the leaf.

Reeling is the chokepoint. A filature needs skilled operators and steady cocoon supply, and once a reeling district closes it does not reopen, because the skills disperse. That is why countries can keep growing cocoons long after they have lost the ability to reel top grades, and why the fine end of the trade has concentrated in China.

The other vulnerabilities are biological and demographic. Egg supply is concentrated in a few grainages, disease moves quickly through crowded rearing rooms, and rearers are aging in most producing countries, a slower and more final constraint than any harvest failure.