Silk is made primarily from the proteins found in the cocoons of mulberry silkworms, also known as Bombyx mori. The worms produce silk fibers from their saliva, wrapping the threads into a protective shell in which they will undergo metamorphosis. Silk makers then process the cocoons, removing and discarding the worms within. The cocoons are then carefully unraveled in order to preserve the threads in their entirety. Because of the long and laborious nature of silk production, there are a number of artificial silk materials on the market as well, commonly referred to as “art silk.” Art silk can be composed of rayon, cellulose, polyester, or some combination thereof and is generally made of crops such as mercerized cotton, wood pulp, or soybeans.

Whether it’s found in clothing, sheets, or pillowcases, silk’s primary points of contact with your body are always going to be on the skin — meaning that your skin will also see the biggest benefits. Silk contains a protein known as sericin, sometimes referred to as silk amino acids, which is commonly used in skincare products to promote skin elasticity and strength. This means that silk products can have a natural anti-aging effect on the skin, halting wrinkle development and keeping things smooth. Another benefit of silk is that it does not absorb moisture from the skin when worn. Some popular materials such as cotton are highly absorbent and draw out water from wherever they’re touching, potentially drying out the skin. In contrast, sericin maintains your skin’s hydration levels and can actually act as a moisturizer in its own right. Full body garments such as silk robes can leverage this property for large portions of your skin. Other garments like silk dresses and tees remain cool and comfortable because of this benefit. Silk’s resiliency extends far beyond water. Its structure doesn’t allow for the levels of buildup of dirt, dead skin cells, or other allergens that most materials do. This decreases the amount of potentially acne or eczema-causing agents your skin is exposed to. Moreover, silk is hypoallergenic, ensuring that your skin avoids irritation at all costs.

Now that you know just how beneficial silk can be, it’s time to get into the nitty gritty of how it works. Chemical properties of silk Silk is composed of two different proteins: fibroin and sericin. About 75% of silk’s mass is fibroin, with the other 25% being sericin. You can think of fibroin as providing the structure of the silk thread — its tough and sturdy nature makes it a great foundation for fiber formation. Sericin, on the other hand, is a sticky substance that binds the thread’s fibers together and helps them form silk as we know it. Physical properties of silk Silkworms weave fibers into a triangle-like pattern which helps give silk threads their natural strength. This structure makes silk one of the strongest natural fibers, though the material is not very elastic: if stressed or elongated, silk will often remain stretched thereafter. The flat surfaces of silk fibers reflect light at certain angles, which gives silk its famous shimmer.

Though mulberry silk is the most common variant of silk available, it is far from the only silk fabric out there. Other silks such as tussah, muggah, and eri silk are also made via similar processes, just with different species of silkworm. Silkworms don’t have a monopoly on the silk making process, though: the silk produced by spiders and even by mussels can also be found in some clothing. The silk’s origin isn’t the only thing determining its type — weave also matters. The most common type of silk is charmeuse, the traditional satin weave most people will be familiar with. Silk can also be found in other weaves such as chiffon, crêpe-de-chine, georgette, and even velvet. All of these weaves differ in texture and are usually used for specific garments or products. How can you tell real silk? Though most products should include labels disclosing their material makeup, it’s not always easy to tell which silk is real and which is synthetic. One easy determinant is price: real silk can be up to 10 times as expensive as art silk. This isn’t surefire though — sellers can simply upcharge art silk in the hopes that people think it’s real! Thankfully, there are a few more tactile tests you can conduct as well. The most famous is the “wedding ring” test: if your silk garment can be smoothly and quickly pulled through a wedding ring, it’s genuine. Artificial silk will scrunch up and often get caught in the ring. You can also crush a bit of silk in between your fingers, too: if you hear a crunching sound, it’s the real deal. Finally, take a close look at the material with a magnifying glass. Real silk will almost always have imperfections in the threading, whereas art silk will be uniform throughout.

Simply put, silk is hard to make. It can take as many as 10,000 silkworm cocoons in order to make a single garment, and those cocoons often need to be unwound by hand or with intricate machinery. These elements can really add up, all resulting in a costly end product. What are other applications of silk? Besides clothing, sheets, and other household fixtures, a number of different areas stand to benefit from silk’s natural properties. The sericin found in silk makes it highly biocompatible, meaning that medical researchers are currently looking for ways that silk could be used within the human body as sutures or other internal structures. Silk can also be processed into gels or films, also useful for medical applications due to their natural makeup.