Latest reviewed evidence
FAO's Silk Reeling and Testing Manual separates cocoon quality, drying, storage, cooking, reeling, rereeling, finishing and raw-silk testing. It reports that cocoon and raw-silk yield, filament length, reelability and quality vary with breed, rearing, mounting, drying, storage and processing; its testing chapter separates size categories and grades through measured lot results. WCO HS Chapter 50 separately classifies reeling cocoons, raw silk, silk waste, yarn and woven fabric. EU Regulation 1007/2011 reserves the textile-fibre name silk for fibre obtained exclusively from silk-secreting insects and restricts pure-composition claims, while FTC guidance requires fiber content, processing or manufacturing origin and responsible-business identity on covered U.S. textile labels. These are identity, classification, testing and labeling references—not certificates for an offered lot, proof of farm or labor conditions, current availability or a live delivered price.
FAO newly evolved hybrid cocoon-shell percentage lower reference
19
percent of whole cocoon weight, lower reference · FAO Silk Reeling and Testing Manual, 1999 edition accessed 2026-09-18
FAO newly evolved hybrid cocoon-shell percentage upper reference
25
percent of whole cocoon weight, upper reference · FAO Silk Reeling and Testing Manual, 1999 edition accessed 2026-09-18
FAO whole-fresh-cocoon raw-silk percentage lower reference
12
percent of whole fresh cocoon weight, lower reference · FAO Silk Reeling and Testing Manual, 1999 edition accessed 2026-09-18
FAO whole-fresh-cocoon raw-silk percentage upper reference
20
percent of whole fresh cocoon weight, upper reference · FAO Silk Reeling and Testing Manual, 1999 edition accessed 2026-09-18
FAO raw-silk first-category ceiling
18
denier, category ceiling · FAO Silk Reeling and Testing Manual, Chapter 11, 1999 edition accessed 2026-09-18
FAO raw-silk second-category ceiling
33
denier, category ceiling · FAO Silk Reeling and Testing Manual, Chapter 11, 1999 edition accessed 2026-09-18
FAO conditioned raw-silk test atmosphere temperature
20
degrees Celsius · FAO Silk Reeling and Testing Manual, Chapter 11, 1999 edition accessed 2026-09-18
FAO conditioned raw-silk test atmosphere relative humidity
65
percent relative humidity · FAO Silk Reeling and Testing Manual, Chapter 11, 1999 edition accessed 2026-09-18
Silk identity begins with species and production system
EU Regulation 1007/2011 defines silk broadly as fibre obtained exclusively from silk-secreting insects, while the FAO reeling manual describes the domesticated Bombyx mori chain from mulberry-fed rearing through cocoon and filament. Atlas retains the declared insect species or accepted commercial type, host and rearing system, crop or season, cocoon origin and supporting records rather than treating the single word silk as proof that mulberry, non-mulberry, domesticated, wild-collected or blended materials are interchangeable.
Cocoons, raw silk, waste, yarn and fabric are separate trade stages
WCO HS Chapter 50 separates cocoons suitable for reeling, raw silk not thrown, silk waste, non-retail yarn, retail yarn and woven fabrics. Those stages carry different units, recoveries, defects, tests and uses. Atlas records the exact stage and transformation path and never transfers a cocoon observation, waste-yarn result or fabric price directly to raw silk or another stage without an evidenced conversion basis.
Cocoon condition controls the downstream evidence chain
FAO treats shell percentage, raw-silk percentage, filament length and reelability as distinct cocoon measures and shows that breed, rearing, mounting, drying, storage and age affect results. Stifling and drying preserve reeling condition, but excessive heat or moisture can damage quality. Atlas retains fresh or dried state, sorting and defect basis, stifling and drying method, dates, moisture, storage, sample and test results with the cocoon lot rather than converting manual reference ranges into a supplier certificate.
Rearing origin, reeling origin and finishing origin remain distinct
Silkworms can be reared and cocoons harvested in one location, dried or traded in another, reeled elsewhere, then thrown, twisted, woven, degummed, dyed and finished in further facilities. A garment's processing-origin label does not silently establish the biological or cocoon origin of its fibre. Atlas preserves farms or rearing clusters where evidenced, cocoon exchanges, reelers, mills, finishers, dates, lot splits and merges, mass balance and custody events as separate origin fields.
Denier, evenness, cleanness and strength belong to a tested lot
FAO's raw-silk testing chapter separates size deviation, evenness, cleanness, neatness, winding, tenacity, elongation and cohesion. It divides raw silk into 18 denier and below, 19–33 denier and 34 denier and above categories, then bases grading on measured results and the lowest applicable class. Atlas retains the cited method and edition, sampling design, conditioned atmosphere, laboratory, result, uncertainty, test date, skein or bale and exact lot; a grade label without those records is not treated as a measured result.
Degumming, throwing, dyeing and finishing change comparability
Raw reeled silk still carries sericin; degumming removes some or all of that gum and changes mass and handle. Throwing or twisting, doubling, spinning from waste, weaving, knitting, bleaching, weighting, dyeing and finishing create materially different products. Atlas retains filament or staple form, twist and ply, yarn count or denier, degumming and boil-off evidence, weave or construction, usable width and mass, colour, finish, treatment and defects before matching offers.
Composition, origin and responsibility claims need their own proof
EU rules reserve the word silk for the defined fibre and restrict 100 percent, pure or all claims to single-fibre products; FTC guidance requires covered U.S. textile labels to state fiber content, country of processing or manufacture and the responsible business. Those destination rules do not prove an upstream species, farm, welfare, labor, organic, recycled or sustainability claim. Atlas keeps composition tests, label basis, processor and custody evidence separate and requires claim-specific substantiation rather than inferring responsible production from a country, brand or certificate logo.
A classification or test manual does not establish a delivered silk price
HS headings, fibre definitions, FAO reference ranges and testing procedures do not establish current availability, lot conformity, transaction value or delivered cost. A physical estimate still needs permitted current observations for the exact species or commercial type, cocoon, raw silk, waste, yarn or fabric stage, quality and test profile, processing and origin chain, package and lot, quantity, currency, Incoterm, load and destination points, delivery window, freight, duties and information vintage. Atlas withholds a physical estimate when those observations or usage rights are missing.