S-Twist / Z-Twist

Ok...so after that so all over the place it wasn't funny post that took me over 4 hours to build... Here's a VERY directed post!

I've had a couple of conversations in the past few months about S and Z twist in spinning. How do you know if the yarn is overspun? What will wash out?

I had the great fortune in January to take a spinning class with Patsy Z, and for the first time I can say that I felt like I truly understood S and Z twist! So, without further ado, here is MY attempt to explain this concept in words (and a few pictures).

First you have the twist of your single ply yarn. If you are planning to make a two or three ply yarn, most people will spin several singles, all with the same twist. Often each of those singles will have "extra" energy in them, which you can release and stabilize by plying that single back with another single in the opposite direction (opposite twist).

So when I spin my single, am I doing S or Z?
Look at the top of your wheel or spindle (on a drop spindle, we would be looking at the far side of the spindle). When you turn it, are you turning it clockwise or counterclockwise? Imagine that we put a mark on one spot on the spindle. As you follow that mark around through your spin, are you beginning the letter S (counterclockwise spin) or the letter Z (clockwise spin)? I believe that most people are trained to spin a single Z - with a clockwise spin. At least that's how I was taught, and that's how I always teach. There may be further implications as to which twist you use (depending on your final application of the yarn - some techniques may tend to untwist a yarn, while others may tend to overtwist it), but I'll admit that I haven't reached that level of understanding yet.

Ok, you've spun your Z single. When you immediately finish spinning, if you leave a long piece of single hanging free, it'll kink up on itself, right? That's because there is extra energy in the single. To see what your balanced, plyed single should look like, as soon as you finish spinning, pull 2 to 3 feet of that single off your bobbin, double it on itself, and let it ply up. Now break off this piece as your "control".


Now let's say we're done spinning for today. Tomorrow come back and pull a foot or two of single off your bobbin. Does it kink up as much if you let it loose? Maybe a little, but probably not nearly as much. This is because the single has settled. The energy is still there, but the single has just sort of fallen asleep and isn't really thinking about that energy anymore.

So now let's take a second single. Maybe you've spun it today, maybe you spun it yesterday or the day before. Some people will say you should make sure that both singles have had some time to rest before trying to ply them together. This way they are more matched as you spin them. I'm not sure I have an experimented opinion on that.

Now take your two singles and begin plying them. Now we'll spin the wheel or spindle in the opposite direction to what we did before. So if we spun Z, we'll ply S or counterclockwise. After you get it started, look at a piece of what you are plying and compare it to your control that we pulled off when the Z twist was live and active. This is what your balanced, finished yarn should look like in terms of number of twists, etc.

You're telling me it should be balanced now, but when I loosen my hold on what I'm plying, it kinks up?
Correct. Remember we said that the Z-twist has gone dormant? Well, the S-twist that you are spinning is live and current, so it will dominate the yarn until we wake the Z-twist back up. That's why your control is so important, since you made it when you had active Z-twist and active S-twist, so it's a true estimate of what your yarn should look like.

Ok, so let's say you've plyed the entire skein, and pull it off onto a niddy-noddy immediately because It's DONE! and you are impatient and want to see it now! (I rarely let a two-ply sit for this very reason!) You tie off your hank and remove it from the nod. Wait a minute here....it's twisting! That can't mean it's balanced, can it? So let's look at how it's twisting. When we look at this sock yarn that I spun, we see a definite twist across the middle of the skein.

The bottom is turned 1 to 2 times from the vertical. Now look at the slant across the skein. Is it the vertical bar of a Z or of an S? Whatever the yarn is displaying to you is what it NEEDS. Basically, it is contorting itself to make up for the twist that it is missing.

So this skein is telling us it needs more Z. Ok, but if you think about it, we already said that the Z twist in this skein, put in yesterday to the single, is dormant! So before we start fiddling with the yarn at all, we need to wake that up and see how it looks THEN!

This skein has now been washed in warm water and a bit of soap. I use SOAK, but Synthrapol is a favorite of many, and shampoo works great too. In part the soap actually helps the wool or yarn to absorb the water. It functions as a wetting agent. I blotted the skein dry in a towel, then took it outside and whipped it over my head to loosen everything back up and let it lie the way it wanted to. And here we have my finished skein!

Wow, look at that. It has almost no twist at all anymore! That means that the goal has been attained and we have a balanced yarn.

If, after washing, we found that the yarn was still overplied, or underplied, now would be a good time to fix it. One way to do this would be to put the hank on a swift (turned sideways at wheel height is ideal) and spin it back to the bobbin. You'll have to determine which way to spin it (is it presenting you with an S or a Z? If it presents a Z, it NEEDS more Z, so you will spin it CLOCKWISE.) Also remember, when fixing the ply, you probably want to add or subtract just a small amount of twist to the yarn, so use a low ratio on your wheel and a very quick take up on the brake so that you are making only a small adjustment to your yarn. Wind off to the niddy-noddy, wash, and analyze again. Depending on the usage of your yarn, a small amount of twist in the finished yarn is not a big deal. Also I will often hang the skein over a clothes hanger, doubled in half, which pulls some of that twist out when drying.

There are different schools of thought on weights attached to your yarn while drying. Personally I feel that if you have a balanced yarn, there is no need to attach a weight to it. Occasionally if I am making do with a yarn that I know is not balanced, I might add a weight (usually two plastic hangers hung from the bottom - so a VERY light weight) to straighten it out a bit. Anything more than that and you probably needed to put it through the wheel again...