S or Z?

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When cotton thread is spun, spinning wheel is used, and it looks similar all over the world. ( http://en.wikipedia.org/wiki/Spinning_wheel ). Turning the large wheel by right hand, and it turns the next wheel(smaller, second wheel) to twist treads, and threads are rolled up on the second wheel. Recently I checked the old Japanese spinning wheel, which was used around here( Kawachi district, which was famous product center of Kawachi Cotton). I understood the mechanism was very simple and reasonable. Cotton fibers are short and uneven, so to make them threads, twisting with this kind of mechanism is necessary

By the way, there are two directions of twisting right twist and left twist.

Usually, right twist is called 'S-Twist', and left twist is called 'Z-Twist'. And some fabrics are made of s-twist threads, and some are made of z-twist threads. I am interested in this difference. Why such difference occurred? I studied for more than couple of months - checked various antique fabrics ( includes Indian Chintz from 18 century) with micro scope, check many books, and most recently, I went to a library and checked antique Kawachi Cotton fabrics collection book. And I found some rules ( of course, I am still studying, and this rule may not be completely right - only a presumption, with quite many exception ).

1)In Japan, usually hand spun cotton threads have s-twist.
2)In India, antique hand spun cotton threads have z-twist.
3)Machine spun threads around Taisho-Showa period have z-twist.

I found an interesting article about natural twist about cotton. Cotton fibers have natural twist themselves, and the direction of the twist is effected and determined by daily rotation, and cotton of north hemisphere have z-twist, and south hemisphere's have s-twist. http://www.jstage.jst.go.jp/article/fiber/60/8/257/_pdf/-char/ja/ (sorry Japanese) In India, earlier than 17 century, thinnest cotton had been hand spun. Most antique Indian Chintz are known to have z-twist. Spinners say to get thin and hard thread, they must twist as the same direction of the natural twist direction. So, this is my supposition, but Indian spinners had to spin with z-twist to get thinner threads as possible as they could.

However, considering the architecture of the old spinning wheel, s-twist seem to be normal. To spin the z-twist, spinner must turn the wheel in the opposite direction or take the belt intersection off ( usually belt between the first and second wheel is crisscrossed to get frictional force).In Japan, cotton fibers were shorter than Indian cotton fibers, and getting thin threads like Indian cotton was impossible, and Japanese spinners had not to pay attention to the natural twist direction. So usually, cotton threads were spun in s-twist, except when the spinners had to spin z-twist threads intentionally.

Spinning machine was imported in early Meiji period(1868-1912). Kawachi ( around our office ) was famous for the cotton production center, and from mid Edo period, cotton was cultivated, and cotton fabrics were hand spun and hand woven for long time. However, I found that 'Hankara'( woven with machine spun warp threads and hand spun weft threads) became the major product already in the Meiji 10(1878).

At the early age of the spinning machine, both s-twist and z-twist seemed to be spun ( I can't find the article about which was the dominance. ) However, after early Taisho period (1912-1916), most spinning machine's direction became z-twist. I know it from couple of books, which were published in early Showa period.

So above three rules seem to be right. Recently I have checked more than several hundred antique fabrics, and know most antique Japanese cotton(which seems to be from earlier than early Meiji) fabrics are spun with s-twist threads. I checked all fabrics of a book about Antique Kawachi Cotton, hand spun cotton (which author wrote so) are woven with s-twist cotton fibers.

However, we already know there are some kinds of exceptions. This letter becomes too long, so we will write about it in the next news letter.

(Above story is about cotton and asa threads. Combination(weaving) of the different directions of the twisted effect to the texture, and especially in the silk weaving, z-twist threads seemed to be often used to weave some kinds of silk fabrics.)

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• Thanks for sharing all these important details for knowing better the history of japanese textiles! -- Xavier Casanova? 2010-01-19 (Tue) 20:35:52

Original text is written by Ichiro on 10th Jan 2010. You can read the original text in this frozen page S or Z?(Original) This site is hosted by ICHIROYA