“Thread stories. Stories about silk: the cultivation of silkworms”

“Ambrogio, like all other farmers, bred a few silkworms every year. At the beginning of May, he formed a stage in some of the rooms of the house using some layers of straw, then he went to the master’s house to fetch the newly hatched silkworms; he took them home, put them on the boards and kept the fire going in the room. Hanging on the wall was a thermometer so that the room was neither too hot nor too cold. Ambrogio plucked the mulberry leaf, and Cristina and Maria peeled it, cut it up, and then fed it to the worms. The silkworm breeder often came to see them, and he always left happy because Cristina kept them well looked after. When the worms were asleep, she gave them little to eat. And when they got up, she put some mulberry twigs and branches on their beds. The worms climbed on them, and then Cristina carried them over other planks to thin them out because they grew bigger and bigger. When the worms were asleep on the fourth day, Cristina ventilated the room. She would not let the silkworms’ bed rot. She swept the planks frequently, removing the worms’ droppings and leaves residues. When the worms were almost ripe, Cristina cooled them. She formed thickets on the planks with twigs of rape or heather or other branches. The groves were never too thick. The spinners went up to the wood and started working. They stretched their threads through the branches, made a cocoon and locked themselves in it. After eight or ten days, the cocoons were collected: the beautiful cocoons were separated from the ugly ones; then, they were put into baskets and taken to the master. When the harvest was going well, Ambrogio received from the master a reasonable sum of money, and with it, he paid off the first debt he had; then he bought some rice, salt, oil, clothes, and other things necessary for the family. He also gave the priest a few liras as alms for some Masses to be celebrated in suffrage of the souls of his poor dead”.

Excerpt from G. Terra, Primo Libro delle Letture Graduate al fanciullo italiano (First book of readings to the Italian child), part added by Master Vittore Brambilla, XXIV Edition, Milan, 1887.

Bombix mori silkworm

Silk is a natural animal textile fibre obtained from the glandular secretions of insects (silk) and molluscs (byssus). Silk is made from the solidified slime that the larva of a lepidopteran insect, scientifically called Bombix mori, produces before beginning its metamorphosis into a chrysalis and then a butterfly. The insect, commonly called silkworm or filugel, feeds exclusively on mulberry leaves and is originally from Central Asia, although it is now bred in the mid-latitudes of several continents.

To say “silks” might be more precise because the filament that is produced by the silkworm is not the only type; for example, other insects include lepidopterans, beetles and spiders, whose valuable threads are mostly used for the production of textiles in the East.

News and interesting facts on the legend and the refinement of a precious fibre.

No other yarn can boast such a significant importance in the history of textile art, so much so as to be traditionally considered the most valuable fibre.

The history of silk has intertwined peoples and entire continents, enriched and connected trade between East and West through the ‘silk road’, and still today arouses profound interest thanks to its symbolic and qualitative value; last among the fibres to enter Europe, it was among those that most marked the history of fashion and costume.

The first fragmentary and uncertain evidence of the use of silk yarns, although often confused between legend and fairy tales, dates back as far as 5,000 years and is found in northern China. Literature attributes the birth of sericulture to the legendary Chinese empress Xi Ling Shi, wife of the Yellow Emperor, ruler of China and first of the five Di. The “Lady of the Silkworms” discovered the qualities of the cocoon and inaugurated the first form of silkworm rearing; the light and impalpable silk clothes, also known as “divine robes”, were reserved exclusively for the Emperor and his inner circle. The secret of silkworm rearing was jealously guarded within the borders of the Empire for more than twenty centuries. Tradition has it that around 550 A.D., two Persian monks, in defiance of strict Chinese laws, smuggled silkworms to the court of Emperor Justinian in Byzantium through holes they had dug in their travelling sticks.

Dalmatic in velvet with silk and gold thread embroidery, from Flanders, 15th-16th century. Trento, Buonconsiglio Castle

Despite this, until the 12th century the East continued to be the largest producer of raw silk. The development of silk production in Italy began with the Islamic conquest of Sicily in 827. Later, around 1100, by the will of the Norman king Roger II of Altavilla, silkworm breeding and spinning became popular in the “Tiraz” (workshops where the actual embroidered fabrics were produced) and later on also in other regions and cities, such as Venice, Lucca and Genoa.

During the Middle Ages and the Renaissance, silk cloths reached extraordinary levels of quality, both for their preciousness and for the refinement of the decorative motifs they were paired with. The fineness, lustre and strength of the yarn made it possible to produce very light fabrics (taffetas) but also very heavy ones (velvets); suffice it to say that three times as much silk was needed to weave a velvet cloth compared to other fabrics.

Due to its high costs of manufacture and to the beauty of the finished products, silk became a symbol of wealth and power, a hallmark of the upper classes. Clothes made of silk textiles, enriched with gilded brocade weaves or embroidery, were the exclusive prerogative of the nobility and the clergy, as opposed to the common people who wore simple dark coloured cloth. In addition to fashion, silk manufacture also flourished in the field of furnishing; if on the one hand the ‘decorative’ use of silk became a real status symbol, on the other hand it also assumed a functional role. Silk, in fact, thanks to its properties and product characteristics, was used as a means of protection from the cold and relief from the summer heat.

Silk textiles, being adorned and thus designed, became an expression of the art bearing messages and languages, unlike cotton and wool textiles.

The agricultural activity of breeding lepidopterans gave rise to many activities such as seed production (butterfly eggs), spinning, twisting, weaving, dyeing, printing and fixing textiles.

Silkworm rearing and cocoon spinning have now almost completely disappeared in Italy and the raw materials are largely imported from China and South America.

The “work” of the silkworm and its finished product.

The art of breeding the Bombix mori, narrated by G. Terra in his stories, finds a certain correspondence with what is reported in the literature of textile merchandising manuals.

Here is some technical information to help you better understand the extract and learn about the processes that lead to the lepidopteran’s “magical” creation of silk.

The bumblebee begins its “work” in spring, when the female butterflies emerge from their cocoons and deposit, after fertilisation, around 500 eggs (“seed” in technical jargon), which have an elongated lenticular shape. In the first few days there is an initial development of the embryo, followed by a long period of latency; usually, to accelerate growth the eggs are heated to a temperature of 24°C, until they become larvae. The worm, having emerged from the seed, is placed on mulberry leaves resting on trellises or mats; here it devours an enormous quantity of vegetables and grows rapidly but after five or six days the larva stops feeding for twenty-four hours. This marks the beginning of the moulting period, which, by repeating itself every week, will bring the worm to its maximum development, and once ready to “ascend to the wood”, it will finally weave the cocoon, from which it will obtain the silk filament produced by two silk glands. The “fake wood” of straw or broom twigs and gorse is used by the moth to climb and weave its scaffolding. It takes about four days for the silkworm to close itself in the cocoon and in this time it can secrete up to 1500 metres of filament. Life inside the cocoon continues with the transformation into a chrysalis or pupa and then into the perfect insect.

Farm families engaged in silkworm breeding and silk processing

To learn more about the treatments and processing stages of silk filaments, don’t miss the next article!

Bibliography:

Buss C., Seta, Oro, Cremisi. Segreti e tecnologia alla corte dei Visconti e degli Sforza,  collana Seta in Lombardia, Silvana Editoriale, 2009.
Devoti D., L’arte del tessuto in Europa dal XII al XX secolo, Bramante Editrice, Milano, 1974.
Terra, Primo Libro delle Letture Graduate al fanciullo italiano, parte aggiunta dal Maestro Vittore Brambilla, XXIV edizione, Milano, 1887.
Maltese C., Le tecniche artistiche, Mursia Editore, Milano, XXIII edizione 2017.
Quaglierini C., Manuale di Merceologia Tessile, Zanichelli, Bologna, 1992.

Web references for photos:

https://theroyalcollection.it/seta/
https://www.researchgate.net/figure/Emperor-Shizong-Ming-dynasty-1368-1644-Hanging-scroll-ink-and-colors-on-silk-2097_fig10_297647263
https://www.artribune.com/arti-visive/archeologia-arte-antica/2019/09/mostra-fili-oro-trento/attachment/dalmatica-fine-xv-sec-inizio-xvi-sec-velluto-ricami-con-filati-di-seta-e-oro-filato-manifattura-delle-fiandre-trento-castello-del-buonconsiglio/
http://www.albarnardon.it/la-bachicoltura-e-la-filatura-della-seta-a-concordia-dal-1600-al-1700/#!prettyPhoto/2/