Look at enough silk pillowcases and you will notice that they are all Grade 6A. Every one. It is printed on the packaging, listed in the specification, and repeated in the description, usually with no explanation of what it means.
It does mean something. It is also not what most people assume. Here is the honest version.
What the grade measures
Silk grading describes the quality of the raw cocoons and the thread reeled from them. The scale runs from 6A at the top, down through 5A, 4A, 3A and lower. A higher grade means the fibre scored better on a handful of physical properties:
- Filament length. How long the unbroken thread reeled from the cocoon is. Longer is better.
- Uniformity. How consistent the thread is along its length. A thread that varies in thickness produces a fabric with a slightly irregular surface.
- Cleanliness. How few slubs, knots and neps are present. These are the small lumps that catch light and, eventually, catch hair.
- Colour consistency. How evenly the raw silk takes dye, which depends on how uniform the fibre was to begin with.
Why length is the one that matters at night
The other three follow from it. A long filament can be reeled into a continuous thread with few joins. A short one has to be spun from pieces, and every join is a weak point and a potential snag.
That difference is invisible when the fabric is new. It shows up after a year of nightly use. Short-fibre silk pills, because the fibre ends work their way to the surface and tangle. Long-fibre silk has far fewer ends to surface, so it stays smooth for longer. This is the single biggest reason two pillowcases with identical weight and an identical price can age completely differently.
It is also why grade and momme are not interchangeable. Momme tells you how much silk is there. Grade tells you how good that silk was before anyone wove it.
The part most sellers leave out
There is no independent body that certifies silk grades. Unlike a textile safety certification, which is issued by a named institute against a published standard, silk grading is an industry convention applied by mills and suppliers.
That has two consequences worth knowing:
- Grade 6A on a listing is a supplier's description, not an audited claim. It is usually accurate, because the mills that produce bedding-weight silk genuinely do work at the top of the scale, but nobody is checking it on your behalf.
- Because it is not audited, the grade alone cannot be the whole answer. It has to sit alongside things that can be verified or felt: the weight of the fabric, the finish, whether the seller will tell you the staple length, and whether the fabric has been tested for harmful substances.
What to do with this
Treat Grade 6A as necessary but not sufficient. If a pillowcase does not claim it, that tells you something. If it does claim it, that on its own tells you very little, because so does everything else on the shelf.
The useful questions are the ones underneath the grade. Is the fibre long-staple? What is the weight? What is the weave? A seller who can answer all three is describing a real product. A seller who can only repeat the grade is reading from a label.
The Aveloor Silk Pillowcase is 22-momme Grade 6A mulberry silk, in 17 colours.
Written by Samuel, Founder.
