How to Tell the Difference Between Silk and Polyester

Silk is an amazing textile. It’s breathable, hypoallergenic, all-natural and beautifully soft. Given its many superior qualities, it’s not surprising that manufacturers have created a host of man-made products that try to mimic the look and feel of real silk. At the top of the list is polyester, a material made from petroleum biproducts that really has nothing in common with silk except texture.
So how do you tell the difference?

Silk is made from the protein fiber produced by silkworms to weave their cocoons. The cocoons are dissolved in boiling water to extract the filaments which are then spun and woven into cloth. This process leaves small imperfections in the weave, variations that can be found in all types of natural fiber. Polyester, on the other hand, is a synthetic material made by heating petroleum biproducts and carboxyl acids to create a polymer compound. This is then stretched into fibers which are either spun or twisted together. The result is a perfectly uniform cloth with no tiny flaws in the weave. Look at the weave. If you can see tiny bumps or uneven threads, it’s more likely to be genuine silk.

Both silk and polyester have a distinct shine. With silk, the shine comes from the structure of the fibers which are like miniature light-reflecting prisms. The shine in polyester varies as a result of blending the polymer with other materials like cotton, satin or real silk. Even on its own, however, polyester is invariably shiny and becomes even more so with wear, age and ironing. Unlike silk, however, the shine in polyester is always “white”. Genuine silk changes color when you tilt it, refracting the light as it passes through the prisms in the fiber. Move the cloth in front of a light source. If the shimmering is just a consistent white shine, it’s polyester. If the reflected light changes color, it’s probably silk.

Most high-quality patterned silks create the design by weaving different colored threads into the fabric. It is possible to print patterns onto silk, however, so seeing a printed design doesn’t automatically mean you’re looking at polyester. There’s an easy way to tell the difference. Printed silk patterns can be seen from both sides of the material while polyester doesn’t allow the pattern to show through to the other side. Turn the material over. If the pattern doesn’t show through, it’s not silk. Most patterned polyester fabrics will simply be backed by a solid color.

If you gently rub a piece of silk, it will feel soft and yielding. Pushing your finger into the fabric, you should feel a slight “give” in the weave. When you rub genuine silk, your fingers will begin to feel slightly warm, something that doesn’t happen with polyester. Rubbing two pieces of silk together should make a crunching sound, a bit like walking on snow or crushing cornflakes. Run the material through your hands and pay attention to the sound it makes and any heat it gives off. If you’re playing with polyester, the result will probably be “nothing”.

It’s not foolproof but checking the price tag is often your first clue to what you’re holding in your hands. Sericulture, the process of raising silkworms for textile production, is an expensive business. Most of the world’s silk is produced in China and India, and there’s an increasing focus on even pricier organic production which is sustainable, humane and uses zero chemicals. All that adds up to a cost that can be ten times as high as polyester, an entirely man-made substance that’s much cheaper to mass produce. If the price is on par with cotton or man-made fibers, it’s unlikely to be real silk. About the only way to get a bargain is to go to the source, and even in Asia silk cloth doesn’t come cheap. 

The ultimate test is to set fire to the cloth, something that’s neither practical nor recommended. Real silk smells like burning hair and produces ash while polyester basically melts and smells like plastic. You shouldn’t have to use a match, however, to know whether you’re getting the real thing. Just take the time to really examine the fabric and be prepared to open your wallet for an item that should maintain its beauty, texture and color for a lifetime.

Now that you’re an expert, you shouldn’t have any trouble recognizing the authenticity of Brave Era’s 100% silk travel sheets. Nothing compares with silk when it comes to hypoallergenic comfort, breathability and luxurious softness. Treat yourself to a great night’s sleep wherever your adventures take you and relax with the comfort of knowing you won’t be bringing home any unwanted companions like nasty bugs and germs.