Silk! A word that evokes images of fine, lustrous fabrics swathed round dark-haired, dusky eyed dames from the Far East. An ancient cloth, it has survived the rise and fall of great dynasties, through to modern times and remains a highly valued commodity even against vast array of synthetics and substitutes. What is this and why is man still so enamoured of this old-fashioned material?
Silk is a natural fibre produced by the larvae (silkworm) of the mulberry moth during the cocoon phase that precedes adulthood. The same word also refers to the textile that is woven from the worms’ fibres. There are other insects that produce silk such as ants, bees, wasps and certain spiders. However, only the mulberry worm is cultivated for textile manufacture.
The worms are reared in farms found mostly in the near and far eastern countries. The moths lay their eggs on a specially created paper, and when the caterpillars hatch they are fed on leaves from mulberry trees. Slightly over a month later the caterpillars – greatly expanded by now – start to spin their cocoons. The cocoon is what comprises the silk and it is produced in liquid form by two glands on the head of the caterpillar. After 2-3 days the caterpillar is completely encased in a cocoon which, if unravelled and stretched out, would be about 1mile long.
The cocoons are harvested by soaking in hot water in order to soften the fibres enough so that they can be unwound into one long string. A single strand is too fragile to use, so several strands are wound together to form usable threads. Some of the cocoons are set aside to produce the next generation of mulberry moths.
This natural fibre has some fundamental features that contribute to its appealing qualities and versatility of use. It has a naturally smooth, soft and non-slippery texture quite unlike a lot of synthetic fabrics. The distinct shimmering appearance is due to the nature of the fibres that refract light shining onto it, thus producing different colours. It can also be dyed into an array of remarkable shades and the resulting threads are then woven into gorgeously coloured materials. These qualities are what make it a very popular fabric for high-fashion garments.
Care must be taken in the handling and storage of this fine material, especially with the pure or near pure pieces. Due to its moderate to poor elasticity, if it is stretched even a little it tends to remain in a permanently stretched form. Perspiration discolours the fabric and excess exposure to sunlight weakens the threads. Also, being a natural fibre, it can be attacked by insects.
Silk is an extremely comfortable fabric to wear in warm climates because of its absorbency. It is also suitable for cold weather because of its low heat conductivity that enables it to retain a layer of warm air close to the skin. Hence it is used to make lingerie, pyjamas and bed sheets.
The beautiful lustre and fall of the material, together with its natural strength, make it an appropriate material for interior fabrics and fixtures: furniture upholstery, wall hangings, floor rugs, curtains and window dressings continue to be manufactured out of silk.