The beginning of silk production in Japan
The oldest example of silk that we know of, was found at a neolithic site in what is thought of today as the cradle of Chinese civilisation. The silk shroud, wrapped around the body of a child, dates back to an incredible 3630BC and was found at the Yangshao culture site in Qingtaicun in Xingyand, Henan.
Model of the Yangshao Culture site where the silk shroud was found. Image by Prof. Gary Lee Todd
According to Chinese legend, silk (in the form that we know it) was discovered somewhere around 2450BC when a silkworm cocoon fell into Empress Xi Ling Shis’ teacup. The cocoon around the silkworm started to unravel and so the Empress decided to spin the thread, which she found produced an extremely strong yet soft cloth. She convinced her husband to give her a grove of mulberry trees, from which she proceeded to breed the worms which made the cocoons. She is attributed with inventing the silk reel which joins the fine individual strands of silk filament into a supple thread strong enough to be used for weaving. For hundreds of years afterwards, only the Chinese royal family was allowed to wear silk.
Empress Xi Ling Shi showing her husband the silkworm cocoons she discovered
The secret of making silk was kept in China for over 2,000 years, with an Imperial law damning anyone who disclosed the secret to death and torture.Due to this, no one is quite sure when the secret of silk production made its way out of China, but we know that by the 4th Century AD it had made its way to Japan via Korea.From here, silk production became an extremely important part of Japanese culture. Harvesting techniques from China and Korea were adapted and refined in order to start producing silk which was considered extremely high quality. Did you know that it takes roughly 35,00 silkworm cocoons to make 5.5kg of raw silk? These 35,000 cocoons are produced by about 30grams of silkworm eggs, which in turn require about a ton of Mulberry leaves to feed on. How insane is that?
Painted panel showing Japanese women making silk
Basic silk production method
To delve into the different forms of silk used in Japanese kimono, we should first briefly cover how silk, in general, is made. The production of silk is known as sericulture, and starts with the cultivation of silkworms, most often the Mulberry Silkworm, or Bombyx Mori. Although they are called silkworms, these critters aren’t actually worms at all but larvae which would turn into a moth given the chance. These larvae produce a protein fiber, mainly Fibroin, when they go into their cocoon stage. This fibroin protein is secreted in a continuous filament from the silkworms salivary glands, along with a gum called sericin which holds the filaments together.
The silkworm moth, Bombyx Mori, with silkworm cocoons
The basics steps to silk production are:
1. A female silk moth lays her eggs (around 300-500)
Japanese workers in 1925 tending to silkworm moths and silkworms
2. The eggs hatch into larvae
Just hatched silkworm larvae are attended to by workers
3. The hatched larvae are fed mulberry leaves. They are amazing eating machines and can eat and breathe simultaneously. They are most hungry just before they make their cocoons. In some cases they are fed up to 10x a day and increase their body weight by about 10,000x in their lifetime.
Japanese silk workers feeding silkworms mulberry leaves
4. After growing and moulting 4 times, the larvae climbs onto a twig and extrudes some fibroin protein to create a net to hold itself and attach itself to the twig
5. The netted larvae then swings itself in a figure 8 pattern while excreting the saliva that will form the silk
6. The excreted saliva solidifies as it comes into contact with the air
7. Over the next 2-3 days the larvae spins about 1 mile worth of silk filament around itself to create a solid cocoon
A silk worker inspecting formed silkworm cocoons
8. The still living silkworm larvae is boiled to remove the sericin and free the filament (killing the poor larvae). This is called the de-gumming process
9. The start of the filament is found by gently brushing the boiled cocoon and is then wound onto a reel
A woman boiling the silkworm cocoons and reeling off the silk filament
10. The single silk filaments are combined to form a strong silk thread
One silkworm cocoon will produce around 1,000 yards of silk filament. The silk filament is known as raw silk and a silk thread is comprised of around 48 individual filaments. The single thread is then woven to produce fabrics. It is interesting to note that as a fabric, silk has some controversy attached to it. Mahatma Ghandi was critical of the process due to his belief to “not hurt any living thing” and instead encouraged people to support wild silk, which can be produced by collecting the cocoons after the silkworm has hatched. PETA has also campaigned against mass produced silk.
Silk in Japan
After its introduction from China, Japan very quickly grew to revere silk and it became an expensive luxury that wasn’t just used for clothing but also in book-bindings, for paintings and calligraphy, for interiors and for a wide range of other objects. By the 19th Century Japan was a major producer of silk and the demand from Europe turned silk into a source of foreign currency. Many of the early trade relationships between Japan and France revolved around the silk trade due to Lyon being the major center of Silk and textile production. At some stage, the silkworms and raw silk purchased from Japan by France accounted for more than ½ the worlds production.Before the 2nd World War, Japan supplied most of the silk used to make silk stockings in Europe.
The Gunma Prefecture has been Japan's main silk producing region since 1872 when the Japanese government built the Tomioka Silk Mill. At the time, this state owned mill was one of the largest and most sophisticated facilities of its kind in the world. Women from all around the country would come to work at the mill. These women were one of the reasons that silk-reeling factories ended up all over Japan as once they left Gunma they would take their knowledge with them. At its peak, the Gunma Prefecture had 25,000 silk raising houses which produced more than 40% of Japan’s silk. This is now on a steep decline as the introduction of Nylon and the desire for western style clothing, along with cheaper imports from China, Brazil and other countries has all but killed the Japanese silk industry.
Color woodblock print depicting the Tomioka Silk Mill
The Gunma Sericultural Experiment Station, which is the sole state owned experiment center specialising in sericulture, is giving the silk industry a new lease on life. They are trying to revitalise the silk industry by creating “value added” cocoons through genetic modification technologies. Some of these technologies aim to induce silkworms to produce high-performance silk materials and proteins for diagnostic agents and cosmetics. Some of these high performance silks include silk 50% thinner than normal silk filaments and fluorescent silks. The research center has also experimented with breeding silkworms with coloured cocoons. To achieve this the silkworms are fed dyes with ground mulberry leaves. Interestingly these amazing creatures don’t always produce cocoons the colour of the dye they are fed. Purple, for example, is produced when the silkworm is fed red and blue dye. People often prefer this method of silk colouration because the silk is dyed to the core and has a more natural colour. This method is also seen as a more sustainable dyeing process when compared to commercially dyed silks. The commercial dyeing methods use huge amounts of fresh water for bleaching and washing, subsequently leaving untreated, chemically tainted wastewater behind which can pollute canals and rivers around the factories.
Pink silkworm and the silk it produces
Common Japanese Kimono Silks
After this overview of the history and production methods of silk in Japan, we thought we’d go into a few of the more common types of silk used in kimono production. First, a very brief explanation of weaving. Weaving is one of the oldest methods of fabric construction, with some evidence suggesting it could date back to Palaeolithic times. An indistinct textile impression has been found at the Dolni Vestonice site in the Czech Republic indicating that as early as 27,000 years ago people where producing plain woven cloth. Weaving cloth consists of a construction method of combining 2 sets of threads, the warp and the weft, at right angles. A loom holds the warp threads under tension, which allows the weaver to pass the shuttle holding the weft thread through the warp threads. With each pass of the shuttle the top and bottom warp thread is alternated to create a sturdy and strong fabric. Now, back to silks!
Warp and weft diagram by Pearson Scott Foresman
Also known as crepe fabric. This is one of the most commonly sold kimono fabrics in Japan, due to it’s wonderful drape and ability to not crease as much as other silks. Chirimen silk is a very traditional weaving technique which creates a fabric with a crimped weave. The raw silk weft threads are twisted, about 3,000-4,000 times per meter, and then woven through untwisted raw silk warp threads. At first, a flat silk fabric is produced. The magic happens when the fabric is washed, and the last of the sericin (remember how we talked about silk production earlier? Sericen is the gum produced by the silkworms to hold the cocoon together) and impurities are washed away. This washing process causes the twisted weft threads to try to unravel themselves, which in turn creates the wonderful “wrinkled” effect so loved by kimono makers. These “wrinkles” in the fabric is called “shibo” in Japanese. There are many variations of chirimen silk, a rougher textured textile is called Oni Chirimen (meaning ogre chirimen) in Japanese. Softer silk is called Hitokoshi Chirimen and is used for more formal kimono. For a more detailed overview of Chirimen silk and the most well know region that produces it see here and here.
2 examples of chirimen silk used in a Japanese kimono
This is another form of chirimen silk which is lighter and finer and often used for kimono worn in the summer. Kimono made with this silk are mostly dyed after weaving, and are perfect for hand painted details as the smooth silk allows for very crisp lines.
Kinsha silk used in two different Japanese kimono
This silk another highly valued form of chirimen silk. The kimono worn by the imperial court were called Omeshi, which is now what we call the heavy silk they were made from. The silk threads are waxed and dyed before they are woven, leaving very little room for error in the weaving process, imagine you had one colour in the wrong place, the whole pattern would be out of whack after that! After weaving, the silk is hand-washed to remove the wax. Due to this work intensive process, new kimono made with omeshi silk are very rare. If you find omeshi silk, most likely you have an older kimono that would have been prized by someone! Antique omeshi kimono are highly sought after and valued by collectors.
Japanese kimono made using omeshi silk
This beautiful silk often used to make wedding kimono or formal robes. After the silk threads are dyed, they are woven into a repeating geometric or floral pattern. This patterned silk is then painted, embroidered or dyed again to create a double design. Rinzu silk ranges from relatively lightweight to super heavy (as is the case with a wedding kimono - more on those here) .
Rinzu silk used for a white kimono
Meisen silk is something we have talked about a bit before (see here) but it is interesting to know that as well as the tie and resist technique, stencils are also used. The threads are loosely woven, then a stencil is applied and the threads are dyed. Sometimes this original stencil is left, but most often the warp or weft threads of the stencil are discarded and new ones are woven in to create the stencil pattern in the fabric itself. Kimono made with meisen silk are often bright and bold, are not worn at formal occasions and were very popular in the 1900s.
Meisen silk Kimono
This is a traditional textile that is produced in the Nishijin district in Kyoto. It is a weaving technique that started in the Heian period over 1200 years ago. To produce this type of fabric, over 20 different steps are taken, meaning this is an incredibly expensive textile to produce. It is very time consuming and the procedures used to make intricate designs can be very specialised. It is most often used for kimono worn at state functions or weddings. Due to its expense nishijin silk is used most often in obi belts. The threads that are used to weave the silk are often thick, and come in many colours but most often the colour used in nishijin silk is gold. This brocade silk is very heavy due to it’s thick threads and layers of embroidery, maybe this is also a reason why it’s often used for obi, imagine having to wear a whole robe of this, so heavy!
Nishijin ori silk on 2 different obi belts
Tsumugi silk was originally made from silk cocoons gathered from the wild. Because these silkworm larvae were allowed to hatch into moths, the cocoons that housed them are broken open meaning that the silk filaments are not continuous. Tsumugi also uses scrap silk filaments left over from cultivated silk production. Because these filaments are much shorter than usual, they have to be joined together more often, creating a rougher and less lustrous silk. Once the silk is spun into a thread, it’s dyed and then starched heavily to to keep the thread together before weaving. Sometimes the silk is then painted or dyed again before the kimono is sewn. I’ve most often seen this silk used for men's kimono, and often they are worn informally. Although the roughness of the silk might make it seem like an inferior quality, it’s actually a more time consuming silk to make and as such is prized for its individuality. The nice thing about this silk is also that the more it’s worn the softer it becomes as the heavy starch disappears.
Two mens kimono made with Tsumugi silk
As with everything that we know about kimono, the silk used in them is a bit of a rabbit hole! Once you start reading you can fall down a hole that takes a while to dig yourself out of... I hope that I’ve managed to cover the basics here so that you can keep from falling in (unless you want to of course). Is there anything else you want to know? DM us on Instagram with your questions!
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