Silk Fabric Quality Standards & Certifications: A Buyer's Technical Reference

Author: 小满 · 燕七 | Date: 2026-07-27

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Quick Reference: Silk Quality Parameters by Application

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Momme Weight: The Fundamental Specification

Momme (mm, 匁) originates from the Japanese silk trade and remains the global standard for silk fabric weight:

Definition: 1 momme = the weight in pounds of a 45-inch-wide × 100-yard-long piece of silk = 4.340 grams per square meter (g/m²).

Conversion: Momme × 4.340 = g/m². 16mm silk = 69.4 g/m².

Momme Selection Guide for Silk Products

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For custom corporate silk fans: 14-16mm is the recommended minimum. Below 14mm, the fabric may show translucency under bright exhibition lighting and is prone to tearing at the fan's fold lines after repeated opening/closing. 19-22mm provides a noticeably more luxurious hand feel and longer lifespan — worth the 15-25% material cost premium for premium corporate gifting programs where the product serves as a lasting brand ambassador.

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Mulberry Silk Grade Classification

Silk grades (6A through 2A) classify raw silk filament quality. The grade determines fabric surface quality, dye uptake, and printing clarity.

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| 6A | >1500m | 0 | Exceptional | 0 | Luxury fabrics, premium fans, haute couture |

| 5A | >1200m | ≤2 | Excellent | ≤1 | Premium products, corporate gifts |

| 4A | >900m | ≤5 | Good | ≤3 | Commercial quality garments |

| 3A | >700m | ≤10 | Moderate | ≤5 | Mass-market items |

| 2A/B | <700m | >10 | Variable | >5 | Budget products, non-garment uses |

For corporate branded silk fans, specify Grade 5A minimum. Grade 6A if the fan features fine-print branding, detailed patterns, or is positioned as a luxury corporate gift. The 5A→6A upgrade adds approximately 20-30% to raw silk cost but eliminates the risk of surface irregularities disrupting printed logos or patterns.

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Fiber Content Verification

ISO 1833 — Quantitative Chemical Analysis

The definitive method for verifying 100% silk claims:

Method for silk/polyester blends: Specimen dissolved in 75% sulfuric acid at room temperature. Silk dissolves; polyester residue is filtered, dried, and weighed. Result = % polyester by difference.

Method for silk/cotton or silk/viscose blends: Specimen dissolved in formic acid-zinc chloride at 70°C. Silk dissolves; cotton/viscose residue weighed.

Acceptance criteria for "100% Silk" label: ≤2% non-silk fiber by weight (measurement tolerance).

Field Verification Methods

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| Burn | Smells like burning hair, leaves crushable black ash, self-extinguishing | Melts into hard plastic bead, chemical smell, continues burning | Burns like paper, gray-white ash, fast burn |

Commercial practice: Never accept "silk" claims without an ISO 1833 lab report from an ISO 17025-accredited laboratory. Field tests are supplementary verification, not contractual proof.

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OEKO-TEX Standard 100 Certification

Tests for harmful substances in finished textiles at every processing stage:

Product Classes

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Key Test Parameters (Class II, relevant to silk)

| Parameter | Class II Limit | Test Method |

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| pH value | 4.0-7.5 | EN 1413 (aqueous extract) |

| Formaldehyde | <75 mg/kg | EN ISO 14184-1 |

| Extractable heavy metals (Sb, As, Pb, Cd, Cr, Co, Cu, Ni, Hg) | Per substance (e.g., Pb <90 mg/kg extractable) | EN 16711-2 (acidic sweat simulant) |

| Azo dyes (carcinogenic amines) | Not detectable (<20 mg/kg per amine) | EN 14362-1/3 |

| Chlorinated phenols (PCP, TeCP) | <0.5 mg/kg (sum) | EN 17137 (LC-MS/MS) |

| Phthalates (sum) | <0.1% (1000 mg/kg) | EN 17137 |

| PFAS (extractable organic fluorine) | <100 mg/kg (targeted PFAS limits apply) | EN 14582 |

Certificate validity: 12 months from issue. Verify certificate on OEKO-TEX online label check: www.oeko-tex.com/en/label-check

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GOTS (Global Organic Textile Standard) Certification

GOTS certification covers the entire processing chain — not just the final product:

Version 7.0 (effective March 2024) Key Requirements:

Fiber Content:

"Organic" label: ≥95% certified organic fibers

"Made with X% organic materials": ≥70% certified organic fibers

Silk must be certified organic (controlled rearing conditions, organic mulberry leaf feed)

Chemical Inputs (processing):

Prohibited: toxic heavy metals, formaldehyde, aromatic solvents, GMO-based enzymes, nano-particles, chlorine bleaching agents, PFAS/PFCs, phthalates, PVC

All chemical inputs must be pre-approved and listed in the GOTS Positive List

Wastewater from wet processing must be treated in a functional treatment plant

Social Criteria:

Employment freely chosen (no forced labor)

Freedom of association and collective bargaining

No child labor (ILO Convention 138 minimum age)

No discrimination

Safe and hygienic working conditions

Living wages (progress toward)

Working hours compliant with national law (≤48h/week + ≤12h overtime)

No harsh or inhumane treatment

Certification scope: GOTS certifies the processing chain (ginning, spinning, weaving, dyeing, printing, manufacturing). Raw fiber itself is certified under organic farming standards (IFOAM family), not GOTS.

For silk fans: GOTS certification means the silk was produced organically from cocoon through fabric, all dyes and finishes are non-toxic, wastewater was treated, and workers throughout the chain were treated fairly. It's the most comprehensive textile certification available.

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Colorfastness Standards

Silk is prone to dye bleeding, especially dark colors on light backgrounds. For branded products with printed logos, colorfastness is critical.

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For corporate silk fans: Rubbing fastness (crocking) is the most relevant — fans are hand-held and the fabric experiences friction during opening/closing. Specify dry crocking Grade ≥4 and wet crocking Grade ≥3-4 minimum.

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Buyer's Test Matrix for Silk Products

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| Corporate Silk Fans | Fiber content (ISO 1833), Momme weight, Colorfastness to rubbing | OEKO-TEX Class II, Crocking dry+wet, Tensile strength (ISO 13934-1) | GOTS, Grade 6A verification, UV aging (ISO 105-B02) |

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Silk Procurement Checklist: 12 Points Before Payment

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*This technical reference covers silk fabric quality standards relevant to B2B procurement as of Q2 2026. Certification standards and test methods are subject to periodic updates — always verify against the latest published versions. Testing should be conducted by ISO 17025-accredited laboratories with relevant scope.*