Fabric Friday: The origin and characteristics of silk

Silk is a protein filament extruded by the larvae of insects, most especially the silk moth Bombyx mori. The moth takes its name from the mulberry leaf on which the larvae feed (Morus is Latin for mulberry). Each larva creates two filaments (fibroin), stuck together by silk gum (sericin) to form its cocoon. The silk filament is reeled from cocoons after the larvae’s development has been stopped. (Some cultivated silk larvae are allowed to develop and emerge as moths for the next year’s egg production.) Warm water is used to loosen and unreel the filament fiber, which includes the gum as well as the silky filament at this stage. The gum is then removed by varying degrees, and at varying stages of production. Silk filament without gum is white; the gum gives the filament an ecru color. The filaments from a single cocoon of one silkworm are on average a mile long, and are strong, glossy and resilient.

Here's a 19th-century image of a Japanese woman reeling silk on a zakuri (silk reel):

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Double cocoons, or ones that became intertwined when the larvae are spinning them, unreel unevenly, with thicker spots in the filament. This type of silk fiber is suitable for weaving doupioni silk, shantung and pongee, where the thick spots show as slubs in the texture.

Here are examples of doupioni silk:

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shantung:

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and pongee:

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The silkworm moth, Bombyx mori, can’t now survive in the wild after being domesticated for such a long time; it is neither camouflaged nor able to fly. Silk fabric is also produced from wild moth larvae, most notably those of the tussah moth. This wild silk is of a very different style and quality.

Here is an example of tussah silk:

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In the long history of silk culture (sericulture), China has always been king. The use and cultivation of silk dates from at least 3500 B.C.E. there.

This is an embroidered silk gauze dating from 4th-century B.C.E., Zhou Dynasty, China:

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The lucrative silk trade reached India, Europe, Africa, the Middle East and North Africa along what was known as “The Silk Road,” beginning during the Han Dynasty (around 200 B.C.E.). For centuries China carefully guarded its silk production method. Silk cultivation was smuggled into Byzantium ca. 550 C.E., and by the 14th and 15th centuries Italy had become known for its fine silks, followed not long after by France and England. At this point China is by far the largest producer of silk, and this not only follows from China’s history of production but also from its relatively large low-wage work force—silk production is labor intensive.

If you want to go down a very deep rabbit hole, the Silk Road is a fascinating subject. It was not just a trade route for silk, spices and other commodities, it has been described as the vascular system of culture. From a University of Oregon class (Life on the Silk Road) description: "Italians learned Persian for better bartering, Mongols crowded to hear the bright melodies of Chinese flutes, and travelers who braved the harsh cold of the Pamir Mountains met with awe the nomads who called the unforgiving peaks their home."

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Remember how there are two types of fiber, staple and filament? Filament is the long one, often measuring hundreds of yards in length. Silk is the only natural filament fiber, but manufactured fibers always start as very long fibers and can be cut as needed. Filament fibers make smooth, strong yarns.

Here is what a silk fiber (A) looks like magnified, next to wool (B) and cotton (C). It's very fine, strong and smooth.

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Many fabrics were originally always woven from silk: Satin, damask, brocade, chiffon, georgette, charmeuse, crepe de chine, gazar, organza, faille, taffeta, and more. You can always look through fabrics by fiber in the Fabric Resource. Here are the silk fabrics: https://vintagefashionguild.org/silk-or-silk-like/

I also want to mention the waste from silk production. A noil is a short fiber that is removed from a yarn in the process of combing. Although they might be considered waste, noils can be used for filling material such as padding, or they can be spun into yarns. Silk noil is made from the noils left over from preparing filament silk.

This is an example of silk noil:

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I'll spare you the details of culinary use of silk pupae—being a vegetarian, that's not my cup of tea.

Let's have some questions and comments, please!

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Thank you, Maggie!

Nothing much to add than to say that the city I live in (Zurich) and the area where I grew up outside the city (Hausen am Albis, home of Weisbrod-Zürrer, is practically next door to where I grew up) have a great history in the production of silk. Whilst St. Gallen was the center for lace production in Switzerland, Zurich was it's equivalent when it came to silk. Last night at the Swiss Textile Collection's event, I got to wear a gorgeous 1980s couture dress made of silk by Abraham, and I got to talk to one of my fellow models who, it turned out, worked for the company in it's final stages. Abraham provided fabrics, mostly silk, to many haute couture houses. Yves Saint Laurent might have been one of their best clients and many well-known designs by him were made of Abraham silk. And Balenciaga's famous silk gazar was developed by Abraham in collaboration with him.

 

Oh, so interesting Karin! I knew of Italian and French silk production—and some England—but Switzerland!

 

Thank you for that tidbit Marian! I haven't read the novel, but it has been on my list forever.

 

And I totally forgot - one of the next events by the Swiss Textile Collection should be a silk history walk around Zurich. I hope it will happen!

 

Thank you so much, Maggie for going deeper into this research on fabrics. So useful to us and most interesting!

 

Fascinating and sad at the same time. I had never heard of tussah silk before. It looks sooo different!
What exactly is raw silk? And how do you tell the difference between it and the slubby silks like doupioni?

 

Thank you so much Mary Jane!

I really really need to get raw silk into our FR—like, today. It is one of the most mistakenly used fabric terms. I believe what most people mean by raw silk is a non-lustrous, nubbly, natural-looking silk fabric. What raw silk is though will never be a fabric type. It is an unprocessed silk filament.

Silk filaments have a gummy outer layer called sericin. If the sericin is left on, the filament is called raw silk. It is removed either at the yarn- or fabric-making stage by washing. Raw silk is not made into fabric. Oh, also, silk from silk worm filaments is naturally white.

Slubs in silk fabrics are formed by the spinning of silk from a double silkworm cocoon, which can’t be unwound evenly in the reeling process, leaving thicker spots in the filaments.

So to answer your question, Victoria, there are no raw silk fabrics.

I know what you mean.

 

Hmm maybe. Or possibly a language thing. There is definitely a type of fabric that I used a literal translation to refer to as “raw” but it must have a different name in English. Wish my mother was alive, she would know. She used to love it.

But you are probably correct in terms of how people use the term here. So what would you call that non-lustrous nubbly kind?

 

I came across a item made of twilled silk printed to look like tussah silk.
This is the printed twill:

This is the tussah silk:


Here is tussah fabric zoomed out—it can be quite elegant.

 

Victoria, do you have any photos of items that you would think were with raw silk?

I think the two most eligible choices are tussah (which could be called wild silk) and noil (which is made from the short waste fibers of silk).

 

I think it’s this but I am trying to research further. I do have a suit made of it. Just need to find it to take a photo.
While trying to research it I came upon the website of the Scientific Center on Sericulture
located in a town known for its silk production in Bulgaria where I am from originally. Some truly fascinating pictures and info about silk production

https://ses-vratza.bacsa-silk.org/e...ta-na-opitnata-stantsiya-po-bubarstvo-vratsa/

 

I see a lot of people call silk noil 'raw silk', such as here.

Code:

https://www.etsy.com/listing/973061165/vintage-raw-silk-skirt-peasant-skirt?ref=search_recently_viewed-2&frs=1

 

I think this item of mine is guilty of being called raw silk.

https://www.etsy.com/ca/listing/809167444/vintage-1950s-yellow-raw-silk-wiggle?ga_search_query=raw+silk&ref=shop_items_search_1

did it again here

https://www.poppysvintageclothing.c...robe-bonnington-m?_pos=2&_sid=19ec97716&_ss=r

 

Generally speaking, I thought I'd heard slightly slubby silks like dupioni or shantung "Rohseide" in German - which translates into raw silk. When I look it, up I'm told it means a) the raw silk filament, like raw silk in English, but b) can also mean a fabric, made of the untreated silk filament - so it seems that fabric made of untreated raw silk does exist - but it's probably not something you'd usually see. Anyway, there are probably some misconceptions around regarding this term, and not just in English.

 

MJ, your man's robe is silk shantung and it's iridescent.

Apparently there is a multi-language issue with the term, from what both Karin and Victoria have said.