How silk is produced
Silk is a very fine, natural fibre, extracted from the cocoon of the silkworm, the larva of the silk moth. The so-called mulberry silkworm produces the most beautiful and high quality silk. The caterpillars pupate, during which time they produce silk through their mouths, which they loop around themselves up to 300,000 times. In order to extract the silk, the cocoons are placed into hot water shortly before the larvae hatch in order to kill the silkworms inside. If this is not done, the caterpillars would rip the cocoons. A cocoon consists of just one unbroken, long thread (filament), which is between 2,400 and 3,000 m long. This silk filament is the finest filament of all natural fibres. There are always around 5-30 cocoons wound or spooled (filament silk) together into a single silk thread, which, after further cleaning, can be processed into textile products. Around 3,000 cocoons (approx. 1 kg) are required to make 250 g of silk fibre. However, usually only 1/3 of the cocoons can be processed in one piece. The remaining 2/3rds, usually from the inner and outer cocoon, are too fibrous and are subsequently spun into a thread (spun silk). This silk is of inferior quality and is not as expensive or treasured as filament silk.
How silk became famous
Silk originally comes from China and was said to have been invented by the Chinese Empress, Si Ling-Chi, who, in the third millennium BC, discovered silk cocoons in her garden and found out how the caterpillars grow and spin the cocoons from thread. She became the patron saint of silkworms and was even worshipped as their goddess. From then on, silk became important in both the economic and social life of China, and demand for it steadily increased. However, for centuries the Chinese kept the secret of extracting silk and it was strictly forbidden to take silkworm eggs out of the country. In ancient times, silk yarns and fabrics were exported out of the country via the well-known Silk Road, making them an important commodity. Transportation over thousands of kilometres was cumbersome and dangerous because marauding thieves constantly threatened the precious cargo. One of the roads led to the Black Sea via Istanbul to Rome. Another led through Baktra and Mesopotamia to the rich cities of Syria and another to the Persian Gulf.
The silk trade
Spices, tea, paper, glass, food and incense were also transported along these trade routes. Silk fabrics were particularly in demand in ancient Rome and they wanted to find out the secret of its manufacture. It was not until around 600 AD that the Arabs brought silkworm eggs to Spain, Sicily and southern Italy, from whence they eventually reached northern Italy as well. This formed the basis for the flourishing silk manufacturing period in the 16th and 17th centuries in Venice, Lucca and Florence. Later, the fine art of silk weaving also reached France, which subsequently became the most important country for producing silk fabrics. In Germany, breeding of the mulberry silkworm began in the 18th century, more than 4,000 years after its beginnings in China. Today, China, India and Japan are the most important countries for silk manufacture. However, the global production of silk is very modest.
