Silk is a very thin, strong, thread-like fibre produced by certain insects and spiders which they use to build cocoons and webs.

Commercial silk is almost entirely derived from the cocoons of domesticated silkworms. The thread is woven into fabric and used to make all kinds of clothing including blouses and shirts, dresses, scarves, sarongs, saris, suits, ties, underwear, and pyjamas. It is also widely used by the textile industry for bedding and other soft furnishings.

Silkworms naturally construct their cocoons while in the caterpillar stage, later emerging as adult moths by breaking through the cocoon wall. This process occurs within a cocoon made of a continuous single strand of white or yellow silk which averages about 1400 metres in length.

On intensive moth farms, this thread is preserved intact for commercial use by killing the pupa with hot air or steam. The cocoons can also be submerged into vats of boiling water with the pupae alive inside. The thread will then be unwound in one long strand. It is estimated that for one metre of silk fabric, 3000 to 15,000 silkworms will be killed.

Alternatives to silk

One sustainable and ethical alternative to regular silk is eucalyptus vegan silk, which is made from Tencel Lyocell fibres. These fibres are derived from the pulp of eucalyptus trees, making them a renewable and eco-friendly choice.

Similar options are bamboo lyocell, cupro (from cotton seeds), orange fibre silk and micro silk - a new material which begins as a protein produced through fermentation using yeast, sugar, and water. The protein is isolated, spun into fibre and made into a material that has the potential to biodegrade.