I returned to knitting in 1999. I started working on how to hand knit objects well suited to keeping fisherman warm on a square-rigged ship, wooden ship. My path included learning to hand spin the kind of yarns used to hand knit objects which could supply the exceptional warmth needed to sail then through storms rather than around storms. I skipped a lot of other basic skills, including socks/sock yarns for urban environments.
In pursuit of warmth, I tried all kinds of yarns, and settled on "gansey" yarn as being a very good yarn for activites away from centrally heated environments. Sailing, snow camping, sheep herding, duck hunting, skiing, and pruning fruit trees in the winter are all activities that can be better enjoyed wearing objects well knit from a good gansey yarn.
The best gansey yarns that I found were the British worsted spun 5-ply, 1,000 ypp yarns made in old mills. By 2004, it was clear that those old mills were disapearing, and I needed to find alternate yarns. I set about learning to spin. It took me 4 or 5 years before I could produce yarns that experienced knitters and spinners could not tell from the commercial products from Britain. It took me a couple more years before I could produce those yarns fast enough that they could be a useful knitting yarn rather than a spinning tour de force.
In the period 2011 to 2020, my normal knitting yarn was some hand spun variation of those yarns. My favorite needles were 2.3 mm spring steel. Certainly, there was a lot of experimentation with finer yarns, often toward 6-ply (3x2-ply cable) 1,700 ypp yarns. These competed with various yarns such as 4-ply Lion Brand Beehive and British Breeds Goosewing yarns, various Blauband, and my hand spun replicas of those yarns. Over the last couple of years, my projects have moved from gansey yarns to finer yarns knit on 1.6 mm needles. While the winter socks I knit fall in 2020 were still 5 and 6-ply yarns at 1,000 and 840 ypp knit on 2.3 mm needles, today all my knitting projects seem to be 6-ply cabled 1,700 ypp knit on 1.63 mm steel needles. I have fallen in love with this 6-ply cabled sock yarn for everything. However, I still pronounce "swatch" as "sock".
Lion Brand Beehive and British Breeds Goosewing have more 'fill', so objects knit from my 6-ply sock yarn have very different behavior and performance. I am struggling with which yarn structures are better for which purposes. I am working this out prior to sampling a lot of 12-ply sock yarn. (e.g., I am knitting my stash of 6-ply cabled 1,700 ypp yarns, ) The knitting bag now holds 1.5mm needles and their knitting sheathes, and cakes of 6-ply sock yarn, before I spin a bunch of 22,000 ypp singles. A bunch of exotic sock and glove yarns have been banished to file drawer with a layer of bay leaves. That hand-spun Irish glove yarn that seems so fine and sophisticated when I bought it in Scotland circa 2004, now seems coarse and pretentious. Bobbins of 11,200 ypp singles are queued up on the tension box - I have some knitting to do.
The grist of my sock yarn is not really that different from "Jumper yarn" used in Fair Isle knitting so knitting a sweater from "sock yarn" is not that outrageous. I knit ~120 to 140 stitches per square inch. And speaking of yarn from the Islands, let us remember that in 1790, Shetland wool was [hand] spun and knitted fine enough that both (together) of the knee-high socks hand knit from hand-spun Shetland wool produced as a gift for the English King would pass through a lady's wedding ring. In this context, what I spin is only coarse stuff, but I practice in hope of doing better. I have been to his Castle, and it is a cold and drafty place (even with modern central heat), and I would rather wear my socks - even in summer, and even if they are thicker.
I find that my handspun yarn produces warmer and more durable fabrics, than commercial sock yarn sold retail, or BeeHive, or Goosewing yarns I can buy. Sock yarns and jumper yarns from commercial mills sold through retail yarn shops ARE likely to produce softer objects than I knit from my hand spun yarns, but I do not find the commercial yarns durable enough to be worth putting the effort into knitting those yarns on fine needles. I find fine spinning is faster and more rewarding than re-knitting - fine objects.
Twist holds yarn together, and fine plies can take more twist than coarse plies. Twist is expensive. Energy to produce twist is traditionally the largest single cost of a wool yarn mill. Putting less twist into yarn means lower cost of production, and making a yarn that can be sold cheaper. On the other hand, it is faster for me to put more twist into my yarns than to reknit the objects.
I can produce a 2-ply, worsted spun yarn at 2,500 ypp or 3-ply at 1,700 ypp, but by the time they are spun and knit tight enough (on US 000 needles) to be a good durable sock yarn, the fabric is unpleasant. However, I find that if I spin 11,200 ypp singles, ply into 2-ply, then make 3x2-ply cable, at ~ 1,700 ypp) I can knit that on those 1.5 mm needles to make dense, cushioning, durable sock yarn. I love it. I do not say it is fast or easy, I say it is a nice sock yarn.
Yes, knitting at 12 spi and 14 rpi may seem a bit tedious, but that is why I put 19-years into learning to use a knitting sheath. And, no, I am not done learning how to use a knitting sheath. In the last few months, I have learned a good bit about the shaping of knitting needle tips for different kinds of knitting. Horses for courses.
Yes, my current sock yarn takes passing 8 yards of yarn through the wheel for every yard of finished yarn. Yes, I block 2 yards of yarn for every yard of finished yarn. Moving to a 12-ply based on 22,400 ypp singles does not change the final grist. The final texture really depends on the ply configuration, ply twist, and cable twist. Knitting effort should not change. These are things to cogitate on and sample as I knit my current sock yarn. Spinning twice as many singles raises spinning effort by ~40%. Considering total effort on the object including knitting effort, that does not significantly change the total effort to produce the object. It is worth while to expend 4% more effort to get 10% ?? more quality.