You buy a pillowcase, sleep mask or scrunchie labeled 100% Mulberry Silk, and at some point you probably wonder:

Is it actually real silk?

There are plenty of tricks online.

Some people say they can tell just by touching it. Some look at the shine. Others immediately reach for a lighter.

We prefer to start somewhere much simpler.

Look at it. Touch it. Move it around in the light.

Mulberry silk has a collection of small characteristics that become much easier to notice once you know what you're looking for.

01 | Start with the shine

Silk has a beautiful sheen, but it doesn't usually look permanently shiny.

Take the fabric near a window and slowly change the angle.

You'll notice the light moving across it.

One area becomes brighter.

Another becomes softer.

Turn the fabric slightly, and it changes again.

It feels less like one flat reflective surface and more like:

light moving through the fabric.

This is especially noticeable on silk satin.

It can be glossy, absolutely.

But the shine still tends to have depth.

Of course, modern polyester satin can be extremely shiny too, so “it's shiny” isn't enough on its own.

Pay more attention to how the light changes when the fabric moves.

02 | Now touch it

This is probably the easiest part.

Mulberry silk usually feels incredibly fine against the fingers.

Soft and smooth, but not necessarily in that ultra-slippery, almost plastic way that some synthetic satins feel.

Try slowly sliding the fabric between your fingers.

Good silk feels smooth, but you can often still feel a tiny bit of natural resistance.

When you first touch silk, it may also feel slightly cool.

Leave it against your skin for a moment, though, and it quickly becomes comfortable.

It's difficult to describe real silk with just one word like “smooth.”

A better description might be:

fine, soft, cool and smooth.

All at the same time.

03 | Pay attention to the weight

Here's something people often forget:

Not all silk feels the same.

A 16 momme silk, a 19 momme silk and a 22 momme silk naturally have different weights and hand-feels.

A 22 momme fabric usually feels more substantial.

There's simply more material there.

So comparing a very lightweight silk with a much heavier piece of polyester satin and deciding that “the thicker one must be real” isn't particularly useful.

It helps to know what kind of silk you're supposed to be holding.

Momme affects the weight, thickness and overall feel of silk.

04 | Let it fall

Pick the fabric up by one edge and let the rest hang naturally.

Silk generally has a soft, fluid drape.

It shouldn't feel stiff or papery.

Give it a small movement and watch how the fabric follows.

For silk used in pillowcases, sleepwear or sleep masks, this softness is often quite noticeable.

A heavier silk such as 22 momme will naturally have a little more weight than a lighter silk.

It doesn't just float.

It falls softly.

That's the difference.

05 | Give it a gentle scrunch

Here's another very simple thing you can try.

Gently scrunch some of the fabric in your hand for a few seconds, then let it go.

Natural silk may hold a little soft creasing.

Usually not a hard paper-like fold, but it may not spring back perfectly either.

Don't take this test too seriously, though.

Weave, fabric weight and finishing treatments can all affect wrinkle resistance.

Think of this one as a small observation rather than a final answer.

That's actually a good rule for checking silk in general:

Don't rely on one clue.

Look at several things together.

06 | Want to go a little further? Look at how the fiber burns

If you happen to have a separate fabric swatch or a few loose threads that won't affect the actual product, you can also observe how the fibers react to flame.

This has traditionally been one way of helping distinguish different types of textile fibers.

Silk is mainly made from protein.

Because of that, its behavior around heat and flame is quite different from thermoplastic synthetic fibers such as polyester.

When it approaches the flame

Silk fibers may begin to shrink or curl slightly.

They don't normally behave like plastic, rapidly melting into an obvious liquid blob.

Once it catches fire

Silk generally doesn't burn particularly aggressively.

Once the flame source is removed, the flame may weaken or go out.

What does it smell like?

This is often the first thing people notice.

Burning silk tends to have a smell similar to burning hair or feathers.

There's a simple reason for that:

they're all protein-based materials.

It's not exactly a pleasant smell.

Actually, it's pretty bad.

But it is quite distinctive.

And what is left behind?

After burning, silk tends to leave a dark, brittle residue.

Touch or crush it gently and it can break apart quite easily.

Polyester and many other thermoplastic fibers behave differently.

They tend to melt under heat and can leave behind a harder, plastic-like bead.

So if what you're seeing is very clearly:

melting → shrinking → forming a hard plastic bead

the material is behaving much more like a thermoplastic synthetic fiber than silk.

07 | Now put all the clues together

We don't really love the idea of using one tiny trick and immediately saying:

“Yep. Definitely real.”

Fabric is a little more interesting than that.

Instead, look at the whole picture.

Look at the shine.

Feel the surface.

Notice that first cool touch against your skin.

Watch how it drapes.

Pay attention to the weight and thickness.

And if you have a separate fabric sample, you can look more closely at how the fibers behave.

When several characteristics all point in the same direction, you have a much better idea of what you're holding.

Before you reach for a lighter, just touch it

If you have a small silk swatch in your hand, the first thing we'd suggest isn't burning it.

Take it to a window.

Turn it through the light.

Touch it.

Give it a gentle scrunch.

Then let it fall naturally from your hand.

That's one of the nice things about silk.

You don't need to know a hundred technical terms before you can start understanding it.

Once it's actually in your hands, you'll already begin to notice what makes the material different.

You can see it. You can feel it.

And sometimes, that's much more interesting than simply reading “100% Mulberry Silk” on a label.