Mulberry raw silk

The most critical quality benchmark is the 6A Grade certification, which represents the highest level of evenness, strength, and cleanliness. Buyers should verify the denier (thickness), typically ranging from 20/22D to 40/44D, and ensure the sericin content is consistent, as this affects the degumming process and final fabric hand-feel. Always request a Uster statistics report to check for imperfections like slugs or knots.

Request a Fiber Identification Test Report from a third-party laboratory. Pure Mulberry Raw Silk is a protein fiber; a common field test is the 'Burn Test', where the fiber should smell like burning hair and leave a crushable black ash. Furthermore, ensure the supplier complies with ISO 15625:2014 standards for silk testing and possesses OEKO-TEX Standard 100 certification to guarantee the absence of harmful chemicals.

For industrial weaving or knitting, you must specify the breaking strength (tenacity) and elongation percentage. High-quality raw silk should have a tenacity of at least 3.5 to 4.5 g/d. Additionally, confirm the winding properties to ensure the silk can be processed on high-speed looms without frequent breakage, which directly impacts production efficiency.

Grade 6A and 5A are primarily used for high-end fashion, bridal wear, and luxury bedding due to their luster and smoothness. Grades 4A and 3A are more economically feasible for interior upholstery, scarves, and blended fabrics. Understanding the end-use allows you to balance economic feasibility with the required aesthetic performance.

The biggest risks are moisture regain fraud and quality substitution. Silk is hygroscopic; ensure the contract specifies the 'Conditioned Weight' (standard moisture regain is 11%) rather than 'Gross Weight' to avoid paying for water. Use Made-in-China.com's Secured Trading services to hold payments until a pre-shipment inspection (PSI) confirms the quality matches your samples.

Silk is a commodity with prices linked to global cocoon market indices. Negotiate based on volume-tiered pricing, but be wary of prices significantly below market averages, as this often indicates lower-grade blending. For first-time buyers, seek a Trial Order MOQ (e.g., 50kg - 100kg) to test the supplier's consistency before committing to container-load volumes.

Raw silk is sensitive to environmental conditions. It must be shipped in moisture-proof packaging (usually PE inner bags and seaworthy cartons or bales). Ensure the shipping route avoids extreme humidity. For documentation, verify if your country requires a Phytosanitary Certificate or specific Rules of Origin documents to benefit from preferential tariffs under trade agreements.

Always conduct a Supplier Audit to verify if the company is a manufacturer (filature) or a middleman. Utilize the Audit Reports available on Made-in-China.com to check their production capacity and export history. Use Letter of Credit (L/C) or Escrow payment methods for large transactions to ensure funds are only released upon presentation of valid shipping documents and inspection certificates.