Ice silk: what it really is, and how to recognise real silk

In short: "ice silk" is not silk. It is the trade name of a synthetic fabric that feels cool to the touch. On 27 September 2026 we opened eight listings sold on Amazon France as soie glacée, the French for ice silk: seven declared polyester or polyamide, often blended with elastane, and the eighth simply wrote "ice silk" as its material, naming no fibre. None named silk as a fibre. To know what you are buying, read the fibre composition, not the product name.

On a product page, "ice silk" sounds like a kind of silk: cooler, lighter, made for summer. You find it on underwear, motorcycle balaclavas, UV-protection gloves, cooling mats for dogs, summer blankets and sleep masks. The word "silk" is there. The silk is not.

What "ice silk" means

"Ice silk" is a trade name, printed as such on some listings. It describes a sensation, not a material: a thin, smooth fabric that feels cool, which sellers present as "cooling" or "breathable".

Here is what the listings we checked on 27 September 2026 declared:

Product sold as "ice silk"	Declared composition
Motorcycle balaclava	Polyester
Boxer briefs, pack of four	85% polyamide, 15% elastane
Mesh boxer briefs	Polyester
UV-protection gloves	Polyester
Cycling caps	92% polyester, 8% elastane
Boxer briefs sold as "luxury"	78% polyamide, 22% elastane
Night caps and an eye mask	Polyester, nylon
Sleep mask	"Ice silk, fabric": no fibre named

Polyamide is nylon: EU law lists both names for the same fibre. Elastane adds stretch. These are common sportswear fibres because they absorb little water. They are not silk.

What the law says about the word "silk"

In the European Union, textile labelling falls under Regulation (EU) No 1007/2011. Four passages are enough to understand the issue.

• Annex I defines silk, under number 4, as "fibre obtained exclusively from silk-secreting insects", in other words from silkworms.
• Article 5(1): "Only the textile fibre names listed in Annex I shall be used for the description of fibre compositions on labels and markings of textile products."
• Article 5(2): "The names listed in Annex I shall not be used for other fibres, whether on their own or as a root or as an adjective." And, more specifically: "The term 'silk' shall not be used to indicate the shape or particular presentation in continuous filament yarn of textile fibres."
• Article 16: the fibre composition "shall be clearly visible to the consumer before the purchase, including in cases where the purchase is made by electronic means".

The word "satin" does not appear once in the regulation. Satin is a weave, not a fibre: a satin can be silk, polyester or viscose.

Remember Article 16 above all. On a shopping site, the composition must be shown before you buy. That line is what counts, not the product name.

How to recognise real silk

1. Read the composition, not the title

Look for the "composition" or "material" line on the listing, or the sewn-in label. Silk states itself in plain words: "100% silk", sometimes "mulberry silk". Words in a title, "silky", "silk touch", "satin", "ice silk", do not describe a fibre. If the composition is missing, ask the seller: it has to be available to you before purchase.

2. The burn test, on a single thread

It is one of the simplest tests you can do at home. Take a loose thread from an inside seam or an offcut, never from the visible fabric. Hold it with tweezers over a sink, away from anything flammable. Burn a warp thread and a weft thread separately: a fabric can mix two fibres, silk and viscose for instance, without it showing.

• Silk burns slowly, with a small flame that goes out on its own very quickly. Its greyish ash crushes easily between the fingers and smells of burnt hair or feathers. That makes sense: silk is a protein, like hair.
• Viscose catches all at once, with a yellow flame, like cotton, and leaves almost no residue. The smell is faint, like burning newspaper.
• Polyester seems to melt and crackles a little. It leaves a black ash that is hard and shiny once cooled, and a sour, slightly vinegary smell that catches in the nose.

These descriptions come from the French-language Wikipedia article on silk, which details how to identify fibres by burning them.

3. Weigh it, if a momme is stated

Momme is a unit of weight: 1 momme equals 4.34 g/m², so 22 momme is 95 g/m². A stated momme can be checked on a kitchen scale, on a simple piece whose surface you know, a pillowcase or a scarf, allowing for the seams. Momme does not tell you everything about a silk's quality, but a figure you can check is worth more than a promise.

What proves nothing

• The OEKO-TEX label. Its STANDARD 100 certifies that a textile has been tested for more than 1,000 harmful substances. It says nothing about composition: polyester can be certified.
• The price. A mask or a pillowcase contains little silk: a low price is not enough to give away a fake, and a high price does not guarantee the real thing.
• The feel. A well-finished polyester satin is smooth and cool under the fingers. Touch points you in a direction; it does not decide.

Ice silk or real silk: what changes for sleep?

This is not a moral question. A cool synthetic fabric can feel pleasant on a hot night, and it costs little. The difference lies elsewhere.

Moisture. Silk has a moisture regain of about 11%: it takes up part of what your skin gives off at night. Polyester is hydrophobic: it absorbs liquids poorly.

Glide. For friction against skin and hair alone, a smooth synthetic does much of what silk does, for far less money. If that is all you are after, it is a defensible choice.

What you pay for. Silk costs more because its fibre costs more. That is only worth it if it really is silk. Hence the one rule that matters: read the composition before you buy.

If you are looking for a mask in real silk, ours is 22 momme mulberry silk, and its composition is on its page: see the Noctya silk sleep mask. To compare it with others, here is our comparison of seven silk sleep masks.

Frequently asked questions

Is ice silk real silk?

No. It is a trade name for synthetic fabrics that feel cool. On the listings we checked, the declared composition was polyester or polyamide, often blended with elastane. Only the composition line tells you the material.

Why is it called "ice" silk?

The word describes a cool feel, which listings push with words like "cooling" or "breathable". It does not name any fibre.

Is an ice silk sleep mask a silk mask?

No, unless its composition says "silk". Of the two ice silk masks we checked, one declared polyester and nylon, the other named no fibre at all.

Are satin and silk the same thing?

No. Satin is a weave, silk is a fibre. Silk satin is silk; a product described as "satin" can also be polyester or viscose. Only the composition tells you.

Does the burn test damage the garment?

No, as long as you burn a single thread taken from an inside seam or an offcut, never the visible fabric. Do it over a sink, holding the thread with tweezers.

Does an OEKO-TEX label prove it is silk?

No. OEKO-TEX's STANDARD 100 certifies that the textile has been tested for harmful substances. It says nothing about its composition.