How fine do I spin my singles to get a target WPI in my plied yarn?

How do you determine singles WPI based on how many plies you want? well, that is in part a function of twist angle or grist, so all I can give you are my ball parks. I tend to spin woolen, for an airy yarn, but will spin high-twist sock yarns. More on twist angle (and yards per pound) in a little bit.

For a two-ply, I estimate my singles at 3/2 the WPI of the result; so for a result of 14 WPI 2-ply (thin end of CYCA 3, which includes DK) I'd want to spin my singles 21 WPI.

For a three-ply, I estimate my singles at twice the WPI of the result; so for a result of 14 WPI 3-ply, I'd spin the singles at 28 WPI.

Mabel Ross (Essentials of Yarn Design for Handspinners) and Anne Fields (Spinning Wool: Beyond the Basics) both give tables in their books that are empirical numbers; if you work out ratios, they are in the neighborhood of my estimates above, though there is variation from WPI to WPI and TPI (twist angle/twists per inch) to TPI -- soo, to continue with all these silly letters, YMMV (grin)

Twist angle/twists per inch has a big impact on yards per pound -- so if you are copying a commercial yarn, this can be a pretty big factor in getting similar YPP for their WPI.

Yards per pound is a function of wraps per inch, twist angle and spinning style: if you spin a lofty, airy yarn that holds alot of air (woolen style), it will be lighter than the same thickness of yarn spun by compressing all the air out of it as you spin (worsted style). So there are huge variations in what the YPP will be for a given WPI; Aldon Amos described it well in his tome, The Big Book of Handspinning. I'm not sure what other references there are for it though I'm sure Mabel Ross (my fave!) touches on it.

I put together a table on CYCA/WPI/YPP a while back in discussing how much fiber you need to get 200 yards of yarn. Here's the data:

Weight WPI YPP
0-lace 24+ 2600++
1-fingering 19-22 2600+
2-sport 15-18 1900-2600
3-DK 12-14 900-1800
4-worsted 9-11 500-1100
5-bulky 7-8 300-500
6-super bulky 6 or less 400 or less

As you can see, those YPP ranges are _really_wide_

Also for those who check details -- there is no CYCA 0, but then again, I guess they don't believe in laceweight yarn? So I made it up since we all love spinning the stuff!

Also also, the plied yarn as spun still isn't "done" -- many yarns will bloom when you wash them so their final post-wash WPI is lower (i.e., the yarn thickens) than their as-spun WPI.

(based on a reply by me on Spin-List)

The picture at the top is a 3-ply superwash merino spun to fingering weight for socks. I plan on churning it in the 72 needle cylinder of my sock machine next-but-one (there's another skein of handspun in line in front of it, for socks for a dear friend). The spinning of that yarn was discussed in Do you really measure twists per inch? ... and you can find several interesting posts by doing a blog search on twist angle. Enjoy!

If you have a rule of thumb for singles' WPI versus 2, 3 or more plies, please add it in the comments here.

5 comments:

Dave Daniels said...

Thank you for this info. For all my spinning, I've never REALLY been sure of which weight category it was.
I feel wicked smaht(<--wicker smart) now, as we say here in Boston.

vicki said...

Thanks for all of your great information! It is really helpful even for those of us her aren't complete novices. Thanks for taking the time it is appreciated.

Abigail said...

thank you so much for this.

i was asking earlier how to figure out what size singles i needed for the size of yarn i was aiming for, and all i got back was "make a sample" and frankly that wasn't very helpful, because i would still need to know what to aim for, all the sampling would do would help me fine tune.

your blog is definitely going into my blog reader and this page into my favorites!

Anonymous said...

Thanks for this chart, I think...
I am soooo confused. WPI seems to me to be so arbitrary; I mean, it just depends on how tightly you wrap those threads, right? So I'm trying to figure out what this thread is that I've spun. It sure seems to be mostly laceweight. (It's a single ply). When I skeined it, it came out to 690 +a bit yds from 8 oz of alpaca/shetland blend that I spun (the thinnest I've ever spun consistently) woolenish. After I finished it, I put it under/over my control card, and it seems to come out around 28. Then I go and look at the chart & come to find out from the yardage (690 x 2 = 1380 ypp) that it's somewhere in the dk range??? OY!!! Like I said, confusion reigns in my brain...

Amelia of Ask The Bellwether said...

for Anonymous ... grist is a tough nut to crack, and that may be why your YPP is in the DK range while your WPI is in the laceweight range. Part of grist is yarn density, and so tightly spun yarn has lower YPP than loosely spun yarn at the same WPI. I'd rely on your WPI test. Yes, those are subjective. How will you know? try knitting it. If the sample works out the way you want it, then you have the yarn you want. Spin on!