Thursday, April 19, 2018

Swaving


Swaving was the last knitting technique that I learned.
One way or another, knitting is a process of using levers to move loops of yarn though other loops of yarn. There are 3 classes of levers. see for example  https://bvg8science.wikispaces.com/file/view/levers.jpg/420871352/476x417/levers.jpg .
I do not distinguish between the various forms of hand held needles.  Hand held DPN, circular needles, and SPN, all have the same physics, (e.g., they act as class 1 levers), and are thereby all the same to me.  Straight DPN used with a knitting belt are class 3 levers. That is very different.  Different techniques using straight needles and knitting sheaths may be class 3 levers or springs and may  have very different physics. In contrast, swaving uses curved needles (Long known as “pricks”) that are rotated in the knitting sheath, and the rotation moves the tip of the needle into the working stitch and slides the new stitch off of the left needle while the motion of the right/shuttle hand, moves the new stitch up the right needle. Still levers, but the axis of rotation, is the fulcrum, and the load is at the tip of the needle.  The process is elegantly fast and simple.  My adding effort to the pricks with the side of my hand, results in compound leverage. I cannot be sure if the "Terrible Knitters" used such compound leverage.

Swaving the foot of the second sock

Mostly the swaving process is driven by both hands and the fabric being moved forward and back, so the fabric pulls the working needle, rotating it and causing the tip of the needle to pop into the next stitch as the fabric is under tension.  (When I need more leverage for tight fabrics, and am using pricks with a small curvature, I give the prick additional “effort” with the side of my right hand.)  The length of the forward and back motion is determined by the curve of the working needle which determines the radius of curvature of the motion. The curve of the prick is chosen depending on the grist of the yarn and the desired knitting gauge. One prick at the V&A has a 90 degree bend and the motion of the tip has a radius of curvature of ~10 cm. I use a ~30 degree bend in my pricks, giving a radius of motion on the close order of 2 cm. With my added effort, the back and forth motion is a fraction of an inch.
I have many old sock needles (short DPN) that I curved to fit my hand better.  These do work with my goose wing knitting sheaths, as class 3 levers, but are not suited for swaving. Long iron or bronze gansey needles will develop a “’J” curve when they are being used for their spring action. Just because someone is using curved needles with a knitting sheath, does not mean they are swaving.  Swaving is about rotating the prick in the knitting sheath.
Swaving is best where one is knitting the same kind stitch repeatedly, i. e., plain knit fabric or garter stitch. It took me a long time to learn to do increases and decreases. I still resort to subterfuge to pickup stitches.  I believe that small changes in technique allow swaving to produce knit fabric with “Eastern”, “Western”, or “Mixed” mounts, but have not studied this.  I am sure that blunt needles tend to enforce a particular stitch mount – it is harder to produce twisted stitches with blunt needles.
That said, swaving is best way I know to make small finely knit items. I often knit the legs of my socks with straight needles (and a knitting sheath), and switch to swaving to quickly knit the the foot. Swaving is without equal for knitting fine gloves.  Certainly, knitting belts are justly famous for the fine Shetland lace, jumpers, and Fair Isle objects produced on them. And, you would not want to try and swave a table cloth or jumper. (Long “pricks” tend to bind, and not rotate properly.) Nor would you want to knit a fine ladies glove from fine (finer than 3,000 ypp ) thread using a knitting belt. (I have never had good luck using needles finer than ~1.5 mm with a knitting belt.) However, swaving makes very fine fabrics on small objects very feasible. Traditional spinners did spin wool into 3-ply yarn at 10,000 ypp .    Shetland wool can be easily hand spun into 2-ply yarn at 15,000 ypp, to say nothing of Merino, camel, guanaco, and silk. My father’s mother loved her fine camel gloves.
I was already swaving with blunt pricks when I was spinning fine, but my knitting in those days was still with “pointy” needles. I have not used straight, “blunt” needles to knit any yarns finer than 5,600 ypp. On the other hand, a review of the old 0.5 mm needles that I was using for fine knitting suggests that they are not really all that “pointy”.  If I were making them today, I would call them “blunt”.  Proficiency in swaving has very much informed my  knitting with straight needles.
Learning to swave was hard. I read what I could find, and I made field trips to places that had collections of traditional knitting tools. However, it is worth noting that museum curators tend not to understand knitting sheath technology. Note the Rutt did not bother to learn to use a knitting sheath.
Making tools for swaving started as extreme trial and error because there was so much diversity in the literature and artifacts in collections such as the V&A.  Once, I had worked out the physics of swaving, it was possible to reverse engineer mechanics that could work for the kinds of fabrics that I wanted.
Same have asked how I know it is “swaving”.  The gross physical motion is right, the tools are right, and the speed is right, and the product is right.  I am going to take it as right, until someone shows me a better way, or I work out a better way myself. I do not claim anything in this blog was or is correct, only that it was or is the best information that I had, or have . There are mistakes, but they are not intentional lies.





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