Silk is a fibre produced by insects when forming cocoons. In the textile industry, the cocoons of silkworms are harvested and transformed into yarn, then woven into fabric.
A popular material for its shine, softness and durability, silk has been used in clothing, upholstery and bedding for thousands of years.
At Sealy, we use silk fibre blends in the quilt layers of some of our mattresses. We choose silk for its resilience and luxurious feel. Learn more in our guide.
What is silk?
Silk is a natural fibre that is harvested for various uses. It is highly sought-after for its softness, shine and durability.
Where does silk come from?
Silk is a naturally occurring fibre, produced by insect larvae and arachnids. Most notably, caterpillars generate silk as a building material for their cocoons. The most common form of silk is obtained from the cocoons of mulberry silkworms.
Although silkworms and other caterpillar species are present in the wild, approximately 2,000-3,000 silkworms are needed to produce a pound (or just under half a kilogram) of raw material. Domestic silkworms are therefore cultivated and reared for their cocoons in an industry known as sericulture.
This practice originated in prehistoric China. There is some evidence for the existence of silk products as early as ~6,500 BC, though early sericulture is dated to the Yangshao era (5,000-3,000 BC). In succeeding centuries, the practice of silk farming spread throughout South Asia, India, the Mediterranean and Western Europe.
Today, China is the world-leader in silk production, followed by India, Uzbekistan, and Thailand.
How is silk made?
Silkworms are fed mulberry leaves before they undergo a moulting process and eventually spin their cocoons. The cocoons are placed in hot water or treated with steam to kill the pupae inside and remove the gum binding the cocoon together.
The individual fibres or filaments of several cocoons are then wound together on a reel to form thread, a process known as reeling. Once this is complete, the threads are ‘thrown’ or twisted together, forming yarn that is strong enough for dyeing, weaving and commercial use.
Like other forms of textiles, silk can be woven by hand or produced in larger industrial settings. While plenty of manufacturing is still performed by hand, the majority of commercial textile production takes place in factories and mills with specialised machines.
What are the fabric characteristics?
Long associated with luxury, silk has a number of lesser-known characteristics in addition to its shine and soft feel. Despite being one of the lightest forms of fabric, silk is particularly strong. Its tensile strength is impressive; silk fibre is shown to be stronger than steel wire.
Silk is also known for its breathability and thermal qualities, making it an ideal choice of clothing for coolness in the summer and warmth in the winter. It is naturally hypoallergenic and is less irritating on the skin than many other types of fabric.
In addition, the material has a high absorbency rate, able to absorb a significant amount of moisture before feeling damp. Even wet through, silk has a fast drying time — contributing further to its popularity and practicality as an everyday textile.
What are the varieties of silk?
There are several varieties of silk. Their characteristics depend on their origin, or which insects are responsible for their production. The most popular is mulberry silk, named for the mulberry silkworms who produce the fibres. This variation of silk is known for its consistent high quality and shine. In addition to mulberry, the main types of silk are eri, muga and tussar.
Eri silk is derived from the eri silkworm in India. This type is coarser than the mulberry variety, and darker in colour. It is known for having excellent thermal properties, and is used widely in clothing and home furnishings.
Muga is a rarer form that has a natural golden colour, produced in smaller quantities in Assam in northeast India. Muga silk is quite glossy and improves in quality as it ages. Because of its continued lustre even after repeated washes, muga is a treasured material, typically used in traditional clothing.
Tussar silk has a golden colour as well, with a coarse or sometimes crisp texture. It is frequently used to make sarees, often dyed in bright colours. Tussar is made from various types of silkworms across Asia.
Additionally, there are a multitude of silk fabrics that differ depending on how they are woven. For example, dupioni is not a specific kind of silk, but a result of using irregular threads with slubs. It is characterised by a thick or often uneven texture. On the other hand, charmeuse is woven in such a way that the front of the fabric is glossy and extremely soft, while the back is more dull and often matte in appearance. Other types of fabric that may be made wholly of silk include chiffon, crêpe, organza, and many more.
What are the uses of silk?
Highly versatile, silk is used in a number of ways from fashion and beauty products to homewares and furnishings.
The lustre of mulberry silk, and the ease with which it can be draped, makes it a popular choice for women’s and men’s clothing. Garments made of pure silk can be expensive, and so they are often seen to be a marker of luxury. This material is featured widely in accessories, sleepwear, high-end fashion and bridalwear.
Beyond clothing, silk is used in high-quality home furnishings such as curtains, bedding, pillows and even furniture upholstery. It is also used industrially in a number of surprising ways, including parachutes, bicycle tires, surgical sutures and soap.
What are the pros and cons?
While silk is a luxurious and beautiful fabric, there are some disadvantages to consider.
| PROS | CONS |
|---|---|
|
Strong Hypoallergenic Moisture-wicking Temperature regulating Soft and smooth texture |
Expensive Delicate laundering May fade in sunlight Prone to water stains |
Is silk sustainable?
Compared to other types of fabric, especially synthetic fibres, silk is a sustainable option because of its natural origins. Pure silk is biodegradable and considered to be a renewable resource.
However, the production process involves killing the pupae inside the cocoon before they hatch. This is done to maintain the quality and length of the fibres. An alternative option is Ahimsa silk, or peace silk, where the pupa is allowed to hatch before the leftover cocoon is used. Ahimsa is preferred by proponents of non-violence and practitioners of Buddhism and Hinduism. Though more ethically sound, this type of silk takes longer to produce, yields smaller amounts of fibre, and costs more to purchase.
What are the alternatives?
There are some fabric alternatives that replicate the softness and sheen of silk. These include satin, rayon, viscose, cupro, and bamboo lyocell, which is a similar material to tencel. There are also some vegan silks made of bananas, pineapples, lotus and cactus.
Sealy and silk
How is it used in mattresses?
We use silk in some of our mattresses, specifically in the quilt layers. Select models include silk as a fibre blend because of its strength and durability, in addition to its soft and luxurious touch. Please contact our team if you would like assistance finding a Sealy product with this material.
Silk FAQs
Can vegans wear silk?
Silk is an animal-based product, made by silkworms who are usually killed during the production process. Many vegans avoid silk for these reasons.
How do you make silk without killing silkworms?
Peace silk, also known as Ahimsa silk, is made without killing silkworms. This type of silk is usually much more expensive, as it is more time-consuming and costly to produce.
Why is silk better than cotton?
Silk is known to feel softer than cotton, with better moisture wicking properties and temperature regulation. It is also more hypoallergenic than cotton.
Is silk natural or not?
Pure silk is natural, derived from silkworms. Silk may be dyed or blended with synthetic fibres. The fabric label should specify whether any synthetic blends have been used.
How to care for silk?
Silk should be hand-washed with delicate detergent in cold water. Hang or lay flat to dry, avoiding direct sunlight. Keep away sharp objects such as jewellery that may snag on the material.
