Spinning Basics: Twist Direction

You may have noticed in the previous post that I spoke about twisting fibers in one direction to spin them and the opposite direction to ply them.

But that gets awfully confusing. How can you tell which direction is intended? How can you describe it to someone else?

Spinners have an easy way of describing it. They call the spin direction either S or Z.

It's easy to understand this. Hold a piece of yarn up so it's vertical. What you'll probably see first is the ply twist. It either slants from upper left to lower right, which is the direction of the center part of the letter S, so it's ply twist is called S.

If the slant is from upper right to lower left, then the twist is called Z twist because it's in the direction of the center part of the letter Z.

If you're testing a singles or something that you need to know which direction to ply in, you can see the fibers going in these directions and you know to ply in the opposite direction.

If you spin or ply Z on a wheel, the wheel (as you view it when you sit at it) will rotate in a clockwise direction. If you spin or ply Z on a spindle, the spindle will rotate in a clockwise direction when you look down on it from above.

S is just the opposite. The wheel will turn counter clockwise. The spindle will turn counter clockwise when viewed from above.

Yarn is traditionally spun Z and plied S. I've read that nobody knows why, but if you spin with a spindle, are right handed, and spin the spindle with a motion like snapping your fingers with your right hand, you'll get Z spun yarn. So, it's easier for a right handed person to spin Z on a spindle, and I think that's where this tradition all came from.

For most uses, twist direction doesn't matter, but using yarn with opposite twist directions in the same piece can make a visible difference in the finished item. The fibers are aligned in a different direction and reflect the light differently, so it looks different. The yarn can be all the same dye lot, but look like different colors. If you've ever knitted a sweater in flat pieces and sewn in the sleeve, you know the sleeve color probably looks slightly different right where the seam is, just because the yarn is going in a different direction, even if it's all the same yarn. So, it's usually considered good to have all the yarn for a project spun and plied the same way.

So, I think those two things started the convention that yarn is always spun Z and always plied S.

However, as with a lot of things, if you completely understand the rules, you can see when it's useful to break the rules. Understanding the rules and knowing when to break them should be part of the definition of being an artist. People learn the rules and never break them. As an artist, I've broken them all the time when it makes a better finished piece.

You could, possibly, knit a sweater in "color work" by using all the same dye lot fiber, but spinning lots in opposite directions and using them as different colors. This would be very subtle, but noticeable. I haven't tried this but it would be an interesting experiment that would probably work best in medium to light colors.

I have also read some articles on crochet that insist that yarn spun Z and plied S will tend to untwist the plying twist when crochet, but that yarn that's spun S and plied Z will tend to tighten up the plying twist when it's crochet. I don't crochet much, and haven't tried this. You spinners who crochet might want to test the truth of this.