How to Identify Real Silk? The Only Definitive Method: The Burn Test

A significant portion of products sold online as "silk" are actually polyester satin, silk floss, or viscose blends. They look shiny and slippery, but they do not provide the benefits that silk offers to your hair, skin, and sleep. So how can you tell if the pillowcase, duvet cover, or scarf you have is real silk? You cannot reach a definitive conclusion by touching it, looking at its shine, or trusting the documents shown by the seller. The only definitive test you can do at home is the burn test.

Short answer: How can you tell if it's real silk?

Take a single thread from the inner seam of the product and burn it. Real silk smells like burning hair and turns into ash that crumbles when pressed with your fingers. Polyester satin, on the other hand, melts like plastic, gives off a sharp plastic smell, and leaves behind a hard lump that does not crumble.

The only definitive method: The burn test

Silk is a protein fiber (just like hair and wool), while polyester is a petroleum-based plastic. When burned, this difference becomes immediately apparent and cannot be imitated. This is why the burn test is the only definitive test you can do at home.

How is it done?

You do not need to cut your pillowcase. Turn the case inside out and carefully pull out one of the loose threads from the inner seam. This thread comes from the case's own fabric and is sufficient for the test. Hold the thread with tweezers, bring the flame close for a short time, and examine the result. Perform the test on a non-flammable surface such as a sink, and keep water nearby. Do not do it around children.

Important: Do not cut a piece of the case's fabric for the test. A single thread taken from the inner seam will give the same result without damaging the product.

How to interpret the result?

	Real silk	Polyester / satin
Burning	Burns slowly, goes out on its own when removed from the flame	Melts, drips, and shrivels with the flame
Smell	Smell of burning hair or feathers	Sharp plastic smell
Residue	Black, brittle ash; crumbles into dust when pressed with fingers	Hard, black, non-crumbling lump

If the residue does not crumble and there is a plastic smell, the product is polyester or a synthetic blend.

Why are laboratory reports and certificates not enough?

Many sellers share a laboratory report or certificate to show that their product is silk. These documents may seem trustworthy at first glance, but they do not prove that the product you have is silk.

A laboratory report can be misleading

Laboratory tests are performed on a fabric sample sent to the laboratory by the manufacturer or seller. The report is only valid for that sample. It does not show that the product sent to you is made from the same fabric. It is possible for real silk to be sent as a sample while a different fabric is used for sale. In other words, the report describes the piece sent to the laboratory, not the case you have in your hands.

The OEKO-TEX® certificate does not say the product is silk

OEKO-TEX® Standard 100 shows that a textile product has been tested for certain harmful substances. It does not certify what fiber the fabric is made from, i.e., whether it is silk or polyester. Polyester fabric can also receive an OEKO-TEX® certificate. Therefore, the phrase "OEKO-TEX® certified" does not mean the product is silk.

In short, no matter how official the documents look, only the burn test can tell you whether the product you have is silk.

These terms do not mean silk

• Satin: A weaving technique, not the name of a fiber. Satin fabric is mostly made of polyester. We explained the difference in our Silk or Satin? article.
• Silk floss: A polyester-based fabric made to resemble silk.
• Silky, silky, silk touch, satin silk: Marketing terms; they say the product feels like silk, not that it is silk.
• Artificial silk (viscose / rayon): A cellulose-based fiber, not silk.

Why is real silk so important?

The benefits of real silk come from its protein structure. It reduces friction on the hair and skin, absorbs and balances moisture, regulates temperature, and does not provide an environment suitable for dust mites. Although polyester satin looks similar, it does not breathe, causes sweating, and does not provide these benefits. This is why it is important to choose a product that is actually silk, not one that "looks like silk". You can find this difference in more detail in our What is a mulberry silk pillowcase? article.

Test Silkshop products yourself

Silkshop has sold only 100% silk products since 2011. We do not use polyester, satin, or synthetic silk-like fabrics in our production. We do not expect you to trust a document for this: Take a thread from the inner seam of the product that reached you and perform the burn test yourself. For details, visit our Genuine Silk Guarantee page.

You can browse silk pillowcases, silk duvet cover sets, and silk duvets.

Frequently asked questions

Is a satin pillowcase silk?

No. Satin is the name of a weaving technique. Most satin pillowcases on the market are polyester. Perform a burn test to be sure.

Does the burn test damage the product?

No. A single thread taken from the inner seam after turning the case inside out is sufficient. Do not cut a piece of the fabric and definitely do not burn the product itself.

Is a product with a laboratory report definitely silk?

No. The report is valid for the fabric sample sent to the laboratory. It does not prove that the product sent to you is made from the same fabric.

Is an OEKO-TEX® certified product silk?

No. OEKO-TEX® is a test performed for harmful substances; it does not show whether the fabric is silk. Polyester products can also receive this certificate.

Why is real silk expensive?

A single mulberry silk cocoon yields a single long fiber that can only be unwound once. Hundreds of cocoons are needed for a single pillowcase. The labor of production and the scarcity of the raw material determine the price.

How is real silk washed?

It should be washed in water not exceeding 30 °C, with a neutral detergent suitable for silk, either by hand or on the delicate cycle of a machine. For detailed information, you can read our How to Wash Silk? guide.