6A Silk is NOT Made From Longest Silk Fibers. So, What is It?

It’s quite common that the silk eye masks, silk pillow or silk bed linen brands claim that their products are made of grade 6A silk. Grade 6A, according to them, is “the top quality silk”.

The first question to see here is:

What is 6A grade silk?

Search “What is 6A grade silk” in Google, and the featured snippet says:

6A Grade Silk is made from the longest silk fibers.

That’s a good starting point.

Instead of having inkling only, it’s better to be an informed customer who knows exactly what it is in the cart before placing an order.

Going a bit deeper, you might also want to know:

  • If the 6A level is the best, what level is the second best?
  • How do I tell that my silk bedding is 6A silk as the merchant said?

Unluckily, Google isn’t able to answer those questions properly.

No worries. Everything you need to know about “grade 6A” is waiting for you below.

Let’s get right in.

What is grade 6A silk?

Let’s start with the first question: what is grade 6A silk.

According to the first Google search result, “6A Grade Silk is made from the longest silk fibres available”.

Looks it makes sense except for the typo fibre.

However, when trying to delve more information about it, the definition is getting increasingly doubtable.

For example, there are barely any results indicating the exact length of silk fiber making “6A silk”, nor other silk quality grades besides 6A; it looks like the only grade mentioned.

It makes us rethink about the credibility of Google’s choice:

Is the silk made from the longest silk fiber 6A grade silk?

The answer is no.

There is no such 6A silk that “is made from the longest silk fibers available”.

Here is the reason:

According to China’s GBT 1797-2008 Raw Silk Quality Standards, the raw silk is divided into 6A, 5A, 4A, 3A, 2A, A, B, C, D, E, and F, a total of 11 grades. The most commonly used 6 grades are from 6A to A. 6A is the grade indicating the best quality.

Instead of silk made from silk fibers, it is the RAW SILK that can be graded 6A. Or, less specifically, the silk fiber can be graded as 6A.

Raw silk, or silk fiber, cannot be made “from the longest silk fibers available”.

Because they are the silk fibers themselves!

Silk made from 6A raw silk

Well, what if the 6A raw silk is used as the raw material to produce silk? Is the resulting silk 6A graded too?

Good question.

Again, the answer is no.

Because the silk fabric quality doesn’t share the same system with silk fiber quality.

Let’ take the silk fabric appearance as an instance. According to GBT 15551-2016 mulberry silk fabrics standard, the system of silk fabric quality on appearance is the 4-point system.

  1. The defect on the silk fabric will be assigned with a corresponding “penalty point” ranging from 1 to 4.
  2. The longer the defect is, the larger the penalty point it will get.
  3. Accordingly, the top silk fabric will feature the lowest penalty point (less than 30 points per 120 sq.yd).

Just like one couldn’t measure water temperature in inch, no silk fabric that could be graded as “6A silk” (in spite of the length of defects it has).

Therefore, in addition to grade 6A silk fiber/6A raw silk, other expressions, e.g. “6A silk” and “6A silk fabric”, are just a little bit less professional.

If you buy the silk bed linen or silk pillowcase from a brand that uses the term inaccurately, probably it’s because they have copied the Chinese silk trader who is unfamiliar with silk fabric production standards.

The longer, the better?

Now we have an idea about what 6A raw silk is.

Next question: what kind of raw silk matches the grade 6A?

We need to review the Google snippet again here, using our new knowledge to improve it:

6A Grade RAW Silk is made from the longest silk fibers available.

Similarly, some other answers talk about the length of silk as well.

Unfortunately, this is another misconception.

Let’s take a closer look at the GBT 1797-2008 Raw Silk Quality Standards.

The GBT 1797-2008 Raw Silk Quality Standards grades the silk according to the results of 10 test items below:

  1. Size Deviation
  2. Maximum Size Deviation
  3. Evenness Change Ⅱ Degree
  4. Cleanness
  5. Neatness
  6. Evenness Change Ⅲ Degree
  7. Winding (Breaks)
  8. Tenacity
  9. Elongation
  10. Defect

Among them, there is no description of length.

It’s reasonable that silkworms that can make longer silk may be healthier than other silkworms, and the silk fiber produced by stronger silkworms may be better.

Yet it is unreasonable to take the length itself as a standard of classification.

Moreover, the average length of silk fiber ranges from 880 to 1,100 yds per cocoon; some can be as long as 1,650 yds per cocoon.

That is to say, the length of the average silk fiber is over 1,300 times longer than your silk pillow, and some long silk fiber is nearly 2,000 times longer than it.

In terms of the quality when using them as different raw materials of a queen size silk pillowcase 30 inch wide, there would hardly be a distinguishable difference.

Therefore, it’s not significant to focus on the raw silk length simply.

Tip: generally, the longest silk is the silk extracted from the cocoon of the male silkworm.

What does Grade 6A mean?

Finally, here is the real answer to what raw silk matches the grade 6A exactly.

The table below describes the test requirements for grades from 6A to F.

Grades of raw silks – GBT 1797-2008 Raw Silk Quality Standard by fao.org

About GBT standards

There are two standards mentioned before: GBT 15551-2016 Mulberry Silk Fabrics Standard and GBT 1797-2008 Raw Silk Quality Standard.

China is the country that formulates both standards.

As China’s silk trade accounts for about 80% of the global silk market, the standards are widely used internationally.

That’s why “grade 6A” is everywhere, yet not much information is available due to the language barrier.

Some other countries that have developed their raw silk quality standards include Italy, India, and Japan.

  • The Italian raw silk electronic inspection grades are from 5 to 0, 6 in total;
  • Indian raw silk grades are 4A, 3A, 2A, A, B, C, D, E, 8 in total;
  • Japanese raw silk grades are from 6A to B grades, 7 in total.

Please note that Japan’s grade 6A raw silk product is way less engaged in global trade.

Japan itself is a traditional country of silk consumption, with silk imports 10 times more than the number of exports.

So, although Japan also has 6A grade available, unless otherwise specified, the term “grade 6A” is based on Chinese standards, and the 6A grade raw silk product is also made in China.

Is my silk bedding made of…

Time to check out whether your silk bedding is made of 6A raw silk or not!

Only 3 steps simply as follows:

  1. Find the supplier of silk fabrics for your bedding brand
  2. Find the supplier who supplies the fabrics silk supplier with raw silk
  3. Examine if they supply fabric manufacturers with grade 6A raw silk

OK… just kidding.

When it comes to the quality of raw material, it’s barely possible of an end-user to figure it out, especially if the above mentioned misconceptions haven’t been cleared beforehand.

The difficulty of judgment and lack of international quality certification consequently create a large number of marketing gimmicks and hypes.

Amazon shows a good example.

Amazon has over 1,000 search results of “6A silk pillowcase”, and over 5,000 search results of “silk pillowcase”.

This quick search on Amazon shows that potentially over 20% of silk pillowcases for sale are “6A grade silk”.

However, according to the 2017 China Silk Industry Development Report, the production of 6A grade raw silk is less than 1% of all production.

Such incoherence shows that we need some other ways to identify the quality of silk beddings.

Some Useful tips

The following suggestions are to help you get the best quality silk bed linen:

Focus on how you feel

If your silk bedding is comfortable to sleep on, there is no need to worry about whether it’s 6A or any grade.

For example, 5A and 6A silk are high-grade silk with an indistinguishable level difference.

Check measurable indicators

You can check out the momme count, or test if it is 100% silk easily.

Have no idea how to measure it out? Check out What is momme count and Is my bedding silk?

Choose higher momme count products

Just as the plastic gemstones do not appear on gold jewelry, the low-grade raw silks would never be used to produce high-grade fabrics, as they are more prone to cause fabric defects and lower the fabric quality.

So, if you prefer high-grade raw silk yet don’t know how to identify one, just choose the silk bedding with a higher momme count within the budget.

Try seamless bedding

The seamless bedding suggests that the weaving machine weave fabric with a larger width.

Those machines are more expensive than ordinary machines, representing a more invested brand.