Saturday, March 07, 2015

Right under my nose

In seeking warmer wool garments, I went to the extremes of modern knitting mythology.  I knit a lot of harsh fabrics where the primary virtue was warmth and durability.  I do not regret this, as those fabrics have kept me warm in real cold, and saved my skin when I fell and skidded down steep rock faces. (Nylon is slippery and it lets one slide faster and faster down the rock or ice, until the nylon wears through and bare skin at high speed hits rock or ice and is turned into hamburger.)

Still most women wrinkle their faces as they touch these fabrics -- for good reason. So the question is: Can one produce such warm fabrics that are soft and friendly?

The answer is yes, and the how was right under our noses all the time. There are actually 3 parts to the how:

  1. Use more plies as you construct the yarn.
  2. Use reasonable fine wool.
  3. Knit reasonably firmly.
Traditional "worsted" weight  knitting yarn was constructed of 6 plies of 5,600 ypp singles. Now, most mill spun yarns of that weight (grist) are only 2-ply. Two-ply yarns are not nearly as warm as yarns constructed from more plies.  This is not my rule, it is Mother Nature's rule; see for details.  I merely recite it.

Reasonable fine wool keeps the yarn from being too harsh.  I may want "rug wool" between me and the rock, but most do not need that kind of durability.

The finer wool and softer yarns have more fill, so the yarn does not have to be nearly as tightly knit to ensure that air cannot easily advect heat through the gaps between the yarns.

I have been testing some commercial Shetland 2-ply jumper weight yarns that run 1800 ypp.  My 3-ply semi-worsted Rambouillet at 1870 ypp is softer, more durable, and much much warmer when knit at the same gauge on the same needles. It is softer, because it is a softer fiber.  It is more durable because there is more twist holding the yarn together.  And, it is warmer because 3-ply yarn has more "fill" than 2-ply yarn.  If you run your thermostat at 72F, you want the Shetland 2-ply jumper weight yarn.  If you run your thermostat at 62F, then you want the 3-ply semi-worsted fine wool yarn.

If I am knitting a fine Fair Isle object from hand spun, then most of the effort goes into the knitting. With a very fast wheel, spinning the singles for a sweater goes from a couple of days spinning for 2-ply jumper weight to ~4 days of spinning for 3-ply jumper weight.  However, an additional 16 hours of spinning is not a big deal compared to the 100 hours of knitting  - if you  consider that the additional spinning time will make the object much warmer and much more durable.  For 20% more effort, one gets 100% more value. The extra effort in spinning, increases the return on the large knitting effort.

On a commercial basis, doubling the required twist  (more and finer plies) would approximately double the price of the yarn, and most knitters would look at the price and decide that the much less expensive 2-ply was warm enough and durable enough.  Thus, the construction of modern commercial yarns is a function of competition and price point, rather then value considering warmth, softness, and  durability. This trade of price point for warmth and durability is a major reason why modern hand knitting is not as warm as the hand knitting in the old days.

Then when winter comes round, modern knitters decide that they need  something warmer and they turn to exotic, expensive, super fine fibers to make warm fabrics.  The problem is that the last few generations of knitters preferred a lower price point over warmth  and  durability, and the mill responded by making 2-ply yarns that are less expensive, but also not as warm or durable.  Likewise, the commercial mills optimized the 5-ply gansey yarns for stitches that "pop" rather than for warmth. The modern commercial 5-ply gansey yarns are much warmer than 2-ply yarns, but they are not nearly as warm as they could be if they were designed to be warm, rather than decorative.

Now, you can take the same semi-worsted, fine wool singles (5,600 ypp) and ply them up as 5-ply and knit the yarn at the same gauge on the same needles as the Shetland 2-ply jumper weight yarns, and you will have soft, dense fabric that is fully 4 times as warm as the fabric from the Shetland yarn.  The fabric is not stiff, it is not harsh, it is just warm.  I have not really run durability tests on it yet, but with all that twist holding the yarn together, it should be much more durable than the 2-ply.  This is a fabric for when your thermostat is set for 52F,

If you can knit the 2-ply at the gauge on the band then you can also knit the 3-ply at the same gauge with the same needles.  By the time you get to knitting 5-ply at that gauge, you are packing the yarn together and will want the leverage of a knitting sheath or at least a leather knitting pouch.

If your thermostat is set at 42F, then move on to real 6-ply, knit on slightly larger needles (3 mm), and enjoy.

If you want to spin your singles from long wool, spun worsted, then the fabric will have less drape, but will be more durable and it will be lustrous.  A stiffer fabric is a small price to pay for warmth that gleams.  Certainly, you can knit it less firmly, but then the fabric will not be as warm.

I would never have gotten here, if I had not been spinning for weaving, and fallen into the habit of plying- up singles spun for weaving as knitting yarns.  I stared spinning semi-worsted 5,600 ypp singles from carded batts to see how they would work as weft, but once I had a few cakes of such singles sitting there, it was very  little effort to ply it up into knitting yarn.

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