Measuring your spinning inch by inch

When handspinners start quantifying the yarn that they have made, there can be a lot of math. Depending on the precision of the measuring equipment and the spinner’s personality there can even be … algebra. I happen to like algebra but I won’t inflict it on you. I would never hurt you like that.

You can use a simple ruler to get some information about how your yarn is spun.  And there won’t be any math. I promise.

Here are two terms that spinners toss around: twists per inch (tpi) and wraps per inch (wpi). They mean very different things. I’m sure that spinners who don’t live in countries hopelessly mired down in the English measuring system (oh how I envy you) would use twists per centimeter and wraps per centimeter. The theory and practice is the same.

Twists per inch is how many times the individual fibers have been twisted per inch of yarn. It is a measure of how tightly spun a yarn is. Wraps per inch is how many times you can wrap a ruler before you cover an inch of that ruler. It is a measure of how thick the yarn is. These two yarns have (almost) the same wraps per inch but different twists per inch.

Let’s take a closer look at these.

Rambling aside point number one: Its much easier to see the individual fibers (and therefore count the twists per inch) if your fiber is not all the same color. For these samples I used a multi-hued alpaca roving. If your fiber is all one color and you can’t see it well enough to get these measurements then… shrug. See the next rambling point.

Rambling aside point number two: Don’t let any of this spin-tech get in your way. People spun for thousands of years before there were handy rulers laying around on every desk and they made beautiful yarn. This kind of analysis is supposed to help you spin the kind of yarn you want. That’s all. If it makes you feel unworthy and keeps you from enjoying spinning then I’ll cut you off. There will be no more learning for you.

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Twists Per Inch (tpi)

My first sample was spun without much twist. I used the lowest speed on my wheel and treadled slowly to put in just enough twist to hold the fibers together.

Sloppy! (I hate yarn like this. The things I do for you readers!) So, I pick out the double bands of black fibers and count them. There is room for some interpretation here (like I said, sloppy) but I see 4 twists in this inch. That’s 4 tpi in the single.

Next its plied and I count the twists again. It always easier to see the twists in plied yarn. I see 6 tpi.

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Now let’s look at the higher twist sample. I used the second speed on my wheel.

(Ahh much better.) I see 8 tpi in this single. I’m counting the light sections. Once its been plied:

I count 7 tpi in this plied yarn. Its also less hairy and the plies have more definition. That is because the single was spun tighter. If you work it up, it will have more bounce, less drape, and better stitch definition than the first sample.

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Wraps Per Inch (wpi)

There are lots of ways to measure wraps per inch (wpi). You can buy a yarn gauge. I have one of those somewhere. Maybe. I think. You can wrap a ruler. That’s what I do. You can wrap a another object, like a pencil or knit needle, and hold it up against the ruler. It all works the same. The point is to lay the yarn side by side and see how many times it takes to cover one inch of space. Don’t pull tight; don’t leave any slack. Just lay it down evenly. To be more accurate, measure the yarn over several inches and take an average.

I tried to spin both samples at the same thickness, the same wpi. I succeeded, almost.

Sample 1 is 12 wpi.

Sample 2 is 11 wpi.

This is where spinners have a good thing going. I’m sure you have all bought yarn that was labeled sportweight and found that it seems to be the same thickness of something you bought last week that was labeled fingering weight. Spinners don’t like meaningless labels, we like cold hard numbers. How thick is the yarn? Its 12 wpi, thank-you very much.

Ravelry is doing a good job of using the wpi system and trying to force it onto the commercial yarn industry. Their classification system:

fingering weight	14 wpi
sport weight	12 wpi
DK weight	11 wpi
worsted weight	9 wpi
aran weight	8 wpi
bulky weight	7 wpi
super bulky	5-6 wpi

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What’s It All Mean?

Sample 1 is sportweight with 4 tpi in the singles and 6 tpi finished.

Sample 2 is DK weight with 8 tpi in the single and 7 tpi finished.

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I hope that was all helpful and not too dull. At least there was no math right? I admit I’m a little concerned that anyone who tries to read this post will fall asleep halfway through.

Here is how the chat between me a Jess went last night:

Me: These pictures are boring.

Me: This post is boring.

Me: Spin-tech is BORING.

Jess: Yeah but people love it.

 Hope Jess is right, lol.

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