What 4A / 5A / 6A Raw Silk Grades Measure, and What They Do Not Tell You

The grade answers one question, not all of them

A grade answers a single question: what quality tier was this lot classified into. It does not answer what you are buying. That gap is where first orders go wrong.

A familiar first order

Consider a first bulk enquiry. A buyer asks for 6A, 20/22D, and a unit price for comparison. The reply comes back with a grade, a denier and a price. The buyer approves. What never reached paper: the variety, the finish, the lot that the 6A claim covers, the grading certificate for that lot, the shade card reference, the HS subheading, or the certificate scope.

Weeks later, a weaving run shows yarn that behaves differently from the approved sample. The buyer asks which lot the 6A claim described. The answer was never written down, because nobody asked for it at the start. The grade was there. The evidence behind it was not.

One root cause behind the confusion

One root cause explains the miss. The grade is the most compact line on a page, so it gets read as a summary of the whole order. A short label that looks complete is easy to treat as complete. The grade is one field inside a larger acceptance framework, and the fields around it are what make a shipment acceptable.

The raw silk spec page publishes that framework in full. It groups the grade with per-batch quality evidence, samples and testing, commercial and shipping terms, and compliance. A buyer who stops at the grade stops one line into the first group. Skimming is rational when comparing several suppliers in one afternoon. It is also the moment the rest of the specification disappears.

The 20/22D white raw silk yarn page shows the product side of the same problem. It lists denier, grade and finish, which is the trio a first pass tends to stop at. The written quotation adds everything else. Read the whole page.

What 4A / 5A / 6A grades measure

The grade is a quality tier assigned to one production lot, following GB/T 1797-2008. It is not a denier, a finish, or a variety. Buyers who ask what the three letters measure get a short, specific answer.

A quality tier assigned per lot

A raw silk grade is a quality tier that classifies one lot of mulberry raw silk yarn. The published spec sheet lists 4A, 5A and 6A as the tiers, and states that grade availability is confirmed by variety in the written quotation. Grading follows GB/T 1797-2008, and moisture is controlled below 11% (Standardization Administration of China, 2008). The certificate check page names that standard as the grading reference.

I will not set out numeric cut-offs between 4A, 5A and 6A here. The test methods and the classification belong to the standard and to the per-lot grading certificate. A sales line that invents a threshold for a tier would be a guess. What a buyer can state safely is narrower: the tier is a lot-level quality classification under a named standard, and the evidence behind it is a test result recorded for that lot.

The test evidence that sits beside the grade

The spec sheet does not leave the grade standing alone. It places grade and quality tier by lot inside a per-batch quality evidence group, alongside evenness, cleanness, neatness, a lot mark, and a grading certificate per lot. Evenness is one of the per-batch quality measures named on the spec sheet. A lot mark is the identifier that ties a grade claim to one production lot. A per-lot grading certificate is the document that records the test result for that lot.

Those six fields answer different questions. The grade names the tier. Evenness, cleanness and neatness record measurable qualities of the yarn. The lot mark ties both to a specific batch. The certificate is the proof. Read together, they turn a three-letter label into a checkable claim. Read alone, the label proves nothing about a shipment you have not received.

What the grade does not tell you

A grade does not fix the denier, the variety, the finish, the lot, the certificate scope, or any commercial term. Each of those is a separate field, and each one has to be on paper.

The table below maps the questions a buyer actually asks to the field that answers them. It is a comparison of coverage, so a buyer can see at a glance how little of an order the grade line describes.

Denier, variety and finish

Denier is a separate row. 20/22D is the standard, with 13/19D also in regular supply and 27/29D available on request. A 6A grade does not say which denier you ordered. The 20/22D white raw silk yarn page shows the product side of that row, and a buyer should check both lines side by side.

Variety is separate too. The product range lists four: 20/22D white raw silk, natural dupion silk yarn, 1-ply luxury silk yarn in 20D and 5 kg bundles, and GOTS-certified organic silk. Grade availability is confirmed by variety in the written quotation, so a 4A, 5A or 6A tier on a list does not promise that tier for a dupion or an organic order.

Finish is a third separate choice. Greige is silk yarn or fabric that has not been dyed. Products can be greige or dyed to order, from a standard shade card or a custom colour, and both options are available on all products. The grade does not carry a colour decision. A buyer who needs a specific shade has to state it as its own field, checked against a lab dip, which is one of the documents listed with the order.

The lot, the certificate and the method

Three pieces of evidence make a grade checkable, and the grade itself is none of them. The lot mark names the batch. The grading certificate per lot records the result for that batch. The test method reference names the standard behind the result, GB/T 1797-2008. On the downloadable raw silk spec sheet, the first two sit in the per-batch quality evidence group and the third sits in samples and testing.

Every field in the framework follows one of two paths. It is either stated in the written quotation, or confirmed in writing before order approval. The written quotation tells a buyer which applies. A buyer should ask for the per-lot grading certificate and the test method reference on paper before approving, because a grade with no lot and no method cannot be checked after the yarn arrives.

Commercial and compliance fields

The grade also says nothing about the transaction. Price and payment terms, incoterms, lead time, packing and bale specification, and HS classification are separate fields. On the trade and shipping terms page, 15-25 working days applies to eligible regular bulk orders after sample, specification, deposit and material availability are confirmed, with the binding schedule in signed order documents. Packing is export cartons or bales, 60 kg per bale typical, and luxury silk yarn comes in 5 kg bundles. Bulk payment is T/T with a 30% deposit and 70% against the Bill of Lading (trade terms, 2026).

Raw silk (not thrown) falls under HS heading 5002, and the exact subheading is confirmed in the written quotation and shipping documents, never one fixed code for every order (World Customs Organization, Harmonized System heading 5002). Compliance is separate again. Certification for qualified buyer review covers GOTS, OEKO-TEX STANDARD 100 Class II, China Organic and quality-system files, within each document's listed scope. Certificate numbers come with the written quotation and the shipping documents. A 6A grade guarantees none of that.

What grade consistency looks like in a finished cloth

A grade tier describes yarn at the reeling stage. The clearest way to see why that matters is a finished cloth with a large, uninterrupted lustrous surface. The site says Yizhou raw silk regularly reaches 5A and 6A, the highest quality tiers, on the raw silk spec page. That is a statement about yarn from one geographic origin, not a claim about any single gown. The site's editorial says the connection runs through "three different crafts but one cloth" (Christopher Bu site editorial, 2026). It states the buyer's point plainly: "A buyer who wants that consistency is really asking for the same origin, not the same style". The same editorial labels the provenance as a first-party record and notes that the label's own production records place the silk for these gowns in Yizhou.

The Forbidden City jacquard gown Fan Bingbing wore to the 2015 Met Gala makes the link concrete. Its palace motif is woven into the cloth on the loom, so the pattern sits inside the weave, and the gown presents a large, uninterrupted lustrous surface where uneven yarn has nowhere to hide. The site notes that a jacquard loom cannot make a clean motif from uneven yarn. On the downloadable spec sheet, the per-batch quality evidence group records evenness, cleanness and neatness, grade and quality tier by lot, a lot mark, and a grading certificate per lot. The evenness and cleanness a buyer checks on paper are the same qualities that let a loom lay a clean palace motif across a broad silk face. The grade tier and the lot mark tie those readings to one batch. Those fields are exactly the ones a written quotation has to state or confirm before a buyer accepts a shipment. The site names three gowns from this one silk base: the dupioni cut for Fan Bingbing in 2013, the jacquard of the Forbidden City gown, and the Snow Plum Blossom dress Paz Vega wore to the 2018 Oscars. Dupioni, jacquard and embroidery all begin from the same reeling and grading, then diverge at the design.

Two limits apply. A grade tier by itself does not predict how a finished garment looks, moves or drapes. The design, the weave and the work added afterwards shape the finished result. On the Forbidden City gown, embroidery was applied only after the jacquard came off the loom. Naming these gowns is not a claim that every gown, collection or runway season used this silk. What a buyer is really specifying, when the quotation asks for a grade and the spec sheet asks for evenness, is the same Yizhou origin recorded per lot from local mills. The grade records the yarn; it makes no promise about a finished dress.

One judgement method: anchor every grade claim three ways

Use one test on every grade claim. Ask for three anchors: the lot, the certificate, and the method.

The methodology is plain. Take a line that says 5A. The lot mark tells you which batch that claim describes. The per-lot grading certificate tells you the recorded result for that batch. The test method reference, GB/T 1797-2008, tells you which standard produced the result. A grade with all three is a checkable claim. A grade without them is a word on a page.

For instance, a buyer comparing two offers can put the three anchors in a short table: lot mark, certificate reference, method. Whichever offer names all three is the one that can be accepted against a specific shipment. The test takes a minute and it separates a specification from a sales line. It also gives the buyer three questions to send in writing, instead of one vague request for a better grade.

Read the grade inside the written quotation framework

The grade is one field in a five-group acceptance framework published on the spec page. Read it in that context, not on its own.

The raw silk spec page sets out five groups: entity and verification; per-batch quality evidence; samples and testing; commercial and shipping; and compliance. Grade and quality tier by lot sits in the second group, together with evenness, cleanness, neatness, lot mark and the grading certificate per lot. Every item in all five groups is either stated in the written quotation or confirmed in writing before order approval.

This is the pointer a buyer needs. The downloadable spec sheet is the source of truth for planning values, such as denier, grades, packing and the standard. The written quotation holds the final values for one order, including grade availability by variety, MOQ, schedule, the applicable HS subheading and certification scope. Comparing a planning value with a final value creates a mismatch that is not really there. The two documents answer different questions.

A buyer can fact check each certificate scope against a public entry before approval. The certificate check page lists the OEKO-TEX label check (OEKO-TEX Association, retrieved 2026-11-06) and the GOTS public licence database (Global Organic Textile Standard, retrieved 2026-11-06). Raw silk grading follows GB/T 1797-2008 (Standardization Administration of China, 2008).

How to specify a grade in a first enquiry

Put the grade in an enquiry as one line among several, and ask for the evidence on paper. Yizhou, Guangxi, is a geographic origin the site uses, and it describes the silk as coming from local mills there. Production origin is one of the entity and verification fields on the written quotation, so a buyer sees it on paper rather than as a marketing phrase.

• State the denier you want, and note whether 20/22D or 27/29D applies.
• Name the variety, and ask whether your grade is available for it.
• State the finish: greige (undyed), a standard shade card reference, or a custom colour to order.
• Ask for the grade and quality tier by lot, the evenness, cleanness and neatness fields, the lot mark and a grading certificate per lot.
• Ask which test method reference the inspection report uses.
• Ask for the certification scope and where the certificate number will appear.
• Keep the spec sheet, the written quotation and the signed order documents together.

The specific action is simple. Before you approve an order, request a written quotation and read the grade line next to the per-batch quality evidence group. The sample request page covers the swatch that should arrive with the quotation. A grade that survives all of those checks is a claim a buyer can accept against a real lot.

Is 6A always better than 4A for my order?

Not as a standalone rule. 4A, 5A and 6A are the tiers listed on the spec sheet, and grade availability is confirmed by variety in the written quotation. Which tier fits depends on the end use and on the per-batch evidence that comes with it. Ask for the lot mark, the grading certificate per lot and the test method reference before you compare tiers across offers.

Does the grade tell me the denier?

No. Denier is a separate row. 20/22D is standard, with 13/19D also in regular supply and 27/29D available on request. A grade and a denier are two different fields, and both should appear in the written quotation.

Is the grade available for every variety?

No. The spec sheet lists 4A, 5A and 6A, and states that grade availability is confirmed by variety in the written quotation. Check the tier against the variety you chose, not against the tier list alone.

Where do I find the numeric limits for each grade?

In the standard and in the per-lot grading certificate. The grading reference is GB/T 1797-2008 (Standardization Administration of China, 2008). This article does not restate test thresholds, because those belong to the standard and to the certificate issued for a specific lot. Ask for the per-lot grading certificate with the quotation.

Does a grade guarantee certification?

No. Certification for qualified buyer review covers GOTS, OEKO-TEX STANDARD 100 Class II, China Organic and quality-system files within each document's listed scope, and certificate numbers come with the written quotation and shipping documents. The grade is a quality tier, not a certificate.