The Silk Cycle
While it wasn’t the only place to produce silk in past times, right now, Freixo de Espada à Cinta has the only Crafts Centre in our country that still develops the cycle of silk in its entirety. Portugal has never been an important European production center for this fiber, but I couldn’t figure out if, to this day, a completely handmade production of silk still exists in France or Italy. Nowadays, the silk that is used in Portugal is mostly imported from Brazil or Turkey, where sericulture is industrial. In the Crafts Centre, Susana, who makes of breeding silkworms her life, was kind enough to arrange a demonstration of the silk extraction for me to watch and observe, while also answering patiently to all my questions. As spring is the time when the caterpillar turns into a butterfly, it was also possible to observe different development stages, since they don’t develop all at the same time.
1. BREEDING THE SILKWORM
Each year, from the butterflies who are born and mate, eggs are collected to breed next year's caterpillars. Larvae are born around April, and then they are put in the center of the treys where they are fed daily with fresh mulberry leaves, free from any kind of moisture. During those weeks, all moisture and temperature conditions have to be carefully monitored. As larvae have different rhythms of growth, it is necessary to separate them into development groups so that is easier to detect when they will start forming the cocoon and also, when they will start breaking from it.
When the caterpillars reach adulthood, rosemary branches are put around the treys to help them root and form the cocoon. They are naturally attracted to the branches and find their own place in them. Caterpillars expel a liquid through their salivary glands which, when twisted and exposed to the air, produces the silk that will form the cocoon and protect them during the metamorphosis. The metamorphosis period takes about 15 days, but most butterflies will never be born, for that would imply the breaking of the cocoon and, therefore, breaking the silk thread.
Producing high quality silk implies the killing of the butterflies while still inside the cocoon. Therefore, using silk, just like using leather, is a decision that lies upon each one’s conscience and sensibility. Knowing when to kill the butterfly requires a close observation of the metamorphosis development. Usually, some butterflies are allowed to be born in order to prove that the process is finished. If the extraction is made too soon, the cocoon turns into dough and it is impossible to spin a continuous thread.
At this point, the rosemary branches with the cocoons are placed outside under the hard sun for a few days, which will kill the butterflies by thermic shock and leave the silk ready to be extracted in the next phase.
2. EXTRACTING THE SILK
In the extraction phase, a copper tin with hot water is prepared to unroll the thread from the cocoon. The water must be at a temperature of approximately 90º, because if it is too cold it won’t release the gum that keeps it together and, if it boils, it will turn the cocoon into a kind of dough, impossible to unravel. A small gorse broom touches the cocoons and collects the threads that will pass through the spinneret and be rolled up onto the skeiner. About twenty threads are spun at the same time, which means that twenty cocoons are used to make one thin silk yarn.
3. REELING, SPINNING, SWIFTING AND WASHING
After removing the skein from the skeiner, just after the extraction, the silk will be the swifted and here begins a continuous process of winding, twisting and stretching that turns 300 thin silk yarns into a white and satiny thread. The high quality silk is reeled into 15 small cards which will then be tied up together and rolled on the bobbin, to the end. Susana keeps her hand wet because it helps the threads bond, while an assistant controls the flux of the threads from the cards, ensuring that they are always together and stretched. When this is over, the silk is ready to be spun; at this point, the 15 threads are still rolled in parallel. To have a strong yarn it is necessary to ply them. The more twisted and stretched the yarn is the more resistant and silky it becomes, raising its quality. With a continuous silk yarn, the spindle rotates and plies very quickly. When well stretched, the silk goes from the spindle to the skeiner, making skeins that will finally be washed and whitened. The skeins are heated in a pot of water and soap for an hour. While they are washed and before they are dried, they will be stretched several times (two people are necessary to do this step) to prevent knots from the plying, which would leave the yarn stained. At last, whitened and dried, the silk is ready to be woven.
( A big thank you to Ana Almeida Pinto for translating this to english!)
Associação para o Estudo, Defesa e Promoção do Artesanato de Freixo de Espada à Cinta
Largo do Outeiro 6
5180-118 Freixo de Espada à Cinta - Portugal
+351 279 658 190
www.cm-freixoespadacinta.pt
