Soy fiber production, according to several sources, goes something like this: After tofu is produced, the factory gathers any remaining residue which is then liquefied and extruded in long strands which are then cut, wet-spun, and acetylated. This process creates filaments which, rather than resembling the staples in something like wool or cotton, are similar to silk in structure and texture. It's a good way to make use of a renewable resource and minimize waste left over from manufacturing tofu. Most of the sources agree that soy fiber yarn is soft like silk, and warm like cashmere. The Southwest Trading Company, which owns the trademark in the United States, markets pure soy fiber yarn--and blends--and soy fiber for spinning; the price of processing soy protein is reflected in the prices of yarn and fiber, which is about $13 for a 200 yard skein.
So how does this tie in with Patons SWS? It's a worsted weight wool/soy blend (70% wool and 30% soy) which is easier to find (for me, at least) than pure soy yarn--it can be found at places like Michaels, as well as at specialty knitting shops, and the price is a bit less than the $13, at about $5 a ball. The yarn comes in a fairly good range of colors including self-striping colorways, most of which are muted; there are more possibilities, however, because it also comes in white and natural, which surely can be dyed if you feel like playing with KoolAid or Wilton cake dyes. The darker colors, however, are rich and inviting. The self-striping colors, rather than having distinct stripes, gradually fades from one shade into another. I must admit, though, that some of the colorways just didn't appeal to me, like the one called Natural Pink. It's more like an Easter-pastel palette for a child's basket because it has green and yellow in it.. melt-away mints, anyone? I really liked the solid colors like Raisin and Indigo, and a few among the stripy ones really appealed to me, too. Particularly the Natural Earth, Denim, and Crimson. Natural Earth was what I used for my test project, which is shown below.
I noted in my review of Lopi yarn that the loosely spun singles split easily and pulled apart with a minimum of encouragement; this was not the case with the SWS, which is also a loosely spun single. While it did split on a few occasions if I got careless with the knitting needles, it was a lot more difficult to pull the strand apart, which meant I could pull the stitches a lot tighter than I could have done with the Lopi. Maybe this was due to the length and structure of the soy filaments and the way they combine with the wool staples? It's not completely unknown for single strands to have slubby sections in them, and I did run into one.. and it was a fairly long, thick one measuring about seven inches. Fortunately, the project I chose for the yarn wasn't one that wasn't extremely dependent on gauge; unfortunately, however, I didn't choose a project that will test how well the yarn breathes or wicks moisture, or the Itch Factor... like socks. I suspect the yarn would work reasonably well for next-to-the-skin garments because of.. well, keep reading.
But the yarn! It's so incredibly soft that the only word I can think of to describe it is luscious. That softness makes it a true tactile pleasure to work with, as does the diminished frequency of yarn pulling apart at the drop of a hat. The only problem, though--and it's not a huge one--is that the yarn is so soft it slides right off metal needles. I had a couple instances where I held up my knitting to see how things progressed, and the needles slipped out and fell on the floor; after that happened twice, I got annoyed and decided to switch to bamboo needles. Bamboo has a less slippery finish than metal--the same thing applies to wood, too--which drags against the yarn enough to keep things from falling off the needles. The stitch definition is pretty good, but the yarn is fuzzy enough to make it act similarly to a mohair or angora blend, which sort of softens the overall result, almost making it seem like a piece of impressionist art. That's probably what Monet would have gone for if he'd been in textiles instead of painting.
So, soy is soft and luscious--can I say it again? Luscious!--and pleasing to the touch as well as the eye. As far as I'm concerned, it's a knitting experience worth repeating.