Silk vs satin eye mask: how to spot real mulberry silk
Most masks sold as "silk" are polyester satin wearing a nicer word. The difference is easy to miss in a photo and easy to feel in the dark. Here is how to tell them apart before you pay for one over the other.
You go looking for a silk eye mask. You find a hundred of them, glossy and inexpensive, and half of them are not silk at all. They are satin. The listing rarely lies outright. It just lets a word do the work, because "silk" sounds like the thing you want and "satin" sounds close enough.
They are not the same, and the gap matters most at the one moment you notice it least: your face, in the dark, for eight hours.
Silk is a fibre. Satin is a weave.
This is the whole confusion in one line. Silk is a natural fibre, spun by silkworms. Satin is a way of weaving threads so one side comes out smooth and shiny. You can weave satin from silk. You can also weave it from polyester, which is what most cheap "satin silk" masks are.
So a satin mask can be made of silk, but usually is not. When a mask is described only as "satin" or "silky," with no fibre named, assume polyester until proven otherwise. Real silk gets called what it is, because the maker paid for it.
Why the difference reaches your skin
Polyester satin looks the part. It is slick and it shines. But it behaves like plastic against you, because it is plastic. Three things separate it from the real fibre:
- Heat. Silk breathes and stays cool against the face. Polyester traps warmth. In an Indian summer, that is the difference between a mask you forget you are wearing and the reason you pull it off at 2 a.m.
- Skin. A smooth surface is kinder than cotton either way, but real silk drags less and holds less moisture, so you wake with fewer pillow-lines around your eyes.
- Hair. Less friction through the night means less breakage and frizz where the strap and edge sit.
Satin gets you some of the smoothness. It does not get you the breathability, and that is usually the part people were actually buying silk for.
How to tell real mulberry silk
You do not need a lab. You need a few checks, and the willingness to ask a question the seller may be hoping you skip.
The burn test, if you already own one
This is the clearest home check, and it costs a single thread. Pull one strand from a seam allowance, hold it with tweezers, and touch a flame to it near a sink.
Real silk smells like burnt hair and turns to a soft, crushable ash. Polyester melts, curls away from the flame, smells like plastic, and hardens into a small bead you cannot crush.
Silk is protein, like your hair, so it behaves like your hair. Polyester is plastic, so it melts. One test, no ambiguity.
When satin is the honest choice
Satin is not the villain here. If all you want is a surface smoother than cotton, at a low price, a polyester satin mask does that. It is a real, reasonable thing to buy.
The problem is never satin. The problem is paying a silk price for it because a listing let you assume. Buy satin knowing it is satin, or buy silk knowing it is silk. Just do not let a word decide for you in the dark.
How we think about it
We are building lull around the things that end a night well, and a mask is the first of them. That means we would rather tell you how to test silk — even silk that is not ours — than sell you a word. A mask sits on your face for a third of your life. It should be exactly what it says it is.
Common questions
No. Silk is a natural fibre spun by silkworms; satin is a weave, and most satin masks are polyester. A polyester satin mask can look glossy and feel slick, but it is not silk and does not share silk's breathability or the way it stays cool against the skin.
Check for a momme weight (19 to 22 for a good mask), a grade such as 6A, and an Oeko-Tex certification. Real silk feels soft and slightly warm rather than plasticky. The burn test is the clearest home check: real silk smells like burnt hair and turns to ash, while polyester melts into a hard bead and smells like plastic.
Momme measures the density and weight of silk. For a sleep mask, 19 to 22 momme is the comfortable range: dense enough to feel substantial and drape softly, without being stiff. If a listing never states its momme, treat that as a reason to ask.
Yes. If your only goal is a surface smoother than cotton, satin does that at a lower price. What matters is knowing what you are buying. Paying a silk price for polyester satin is the thing to avoid.
We are making the mask we would test for.
lull is building the small things that end a night well, starting with the one that covers your eyes. Come be first.
Get early access