How do I spin for a sweater?

By Amelia © November 1, 2013

A ravelry member contacted me recently: she had the perfect sweater pattern, and wants to spin the yarn for it. Her question was: How do you make sure your handspun yarn will work, and that you have enough?

To spin yarn to substitute for a commercial yarn, there are several things to measure: fiber, yarn thickness, yarn construction, and amount of twist. Most of them lead you back to grist.

Ahh, grist. I didn't get what grist was about as a "young" spinner. It wasn't until I started spinning tapestry yarn on commission that I realized how important grist was.

Grist is a measure of yarn density, relative to yarn thickness. It is measured by yards-per-pound. It's a bit of a tricky duck -- I can have two yarns with different thicknesses and the same grist. The thicker yarn has more air in it, or a less dense fiber. How can fibers have different density? Easily. Angora fiber, for example, has a hollow core. So it has a definite lightness to it. Alpaca fiber is quite dense, so it drapes really well,  almost flowing over whatever it is placed on -- its own weight pushes it down. That's part of why alpaca sweaters "grow".

First, if the pattern lists a commercial yarn, then look at the fiber content of that yarn. If it's acrylic, medium to fine wools should spin up with a similar grist. If it's a wool/alpaca blend, then start there, with wool and alpaca. Then, look at the yards in a ball of the yarn relative to the skein's weight. If it's 400 yards in 8 ounces, then multiply by two to get the yards in a pound: 800 yards in 16 ounces. So, that yarn would be 800 yards per pound (ypp).

So, choose a fiber similar to the fiber in the commercial yarn. This is so you have less issue spinning to match both the thickness of the yarn and its grist. It's important to match yarn thickness so you can match the gauge it calls for -- if you don't match both stitch and row gauge, the shaping in the pattern as written won't work. That would mean figuring out how to redo the shaping.

Then, see if you can find out the yarn construction of the commercial yarn. 2-ply? 4-ply? a 6-ply cable yarn?  The yarn construction tells you a bit about the roundness of the yarn, as well as its toughness. As a straight plied yarn (not cabled), the more plies there are, the rounder the yarn is. A single, though, is the roundest yarn (obviously...). If the yarn is 3 or more plies, I will usually spin a 3-ply yarn and call it good enough. I only spin a 2-ply when matching a commercial yarn if it, too, was a 2-ply. That's because 2-ply yarns knit into a flatter fabric -- my row gauge is likely to be off if I use a 2-ply in a pattern that calls for a 4-ply yarn. I spin a single when the commercial yarn was a single, or one of the faux-singles which are actually an odd 2-ply with the same direction in the singles and the ply.  

Cabled  yarns are very strong. Usually, a commercial cabled yarn is cabled due to the fineness of the fibers -- many thicker cotton yarns are cabled yarns. Some sock yarns are cabled for strength. If I'm just not up for spinning a cable, I will add strength to the yarn by  spinning with a high twist. Cabling also compresses down the yarn quite a  bit, so I will also pick a denser fiber if I  am choosing not to cable the yarn.

Many commercial yarns just say "wool", without providing a breed. And different breeds will have  different densities in yarn. From more  dense to left, we have longwool,  medium wool, and fine wool. There are some outliers -- high crimp down breeds are less dense than other medium wools, as their high crimp keeps a lot of room in the yarn for air; and Shetland, a fine wool, has less crimp than other fine wools, so spins into a denser yarn. It will be up to you, to decide what to use. If you can feel the commercial yarn, you can decide what class of wool might work best. Or, you might be spinning the yarn because you need to use merino for softness or want to use a superwash so it will be washable.

When yarns provide percentages for fiber content, those are by weight -- so a 60/40 wool/alpaca yarn is 60% wool by weight. That means when you blend fibers to match the yarn's  content, you would weigh out 6 ounces of wool for every 4 ounces of alpaca.

Finally, you need some idea of the thickness of the yarn. If you have a sample, you can measure the wraps per inch (here's how: ). You can use the Craft Yarn Council of America's standard yarn sizes to determine what wraps per inch range should work, as shown on that link. Or you may find WPI information about the yarn on's yarn database. 

The last piece of information is the amount of twist in the final yarn, and any information about finishing that might be discernable. There is no general inclusion of twist information on the yarn ball band. However, pictures will give you a general idea of low twist or high twist. Low twist yarns tend to look  puffy in the ply; high twist yarns look shiny due to the smoothness the high twist puts on the surface of the yarn and how compressed the singles are in the ply structure. The item itself may give an idea about twist amount: socks are best knit with durable yarns, which typically have high twist. Sweaters with cables need fairly crisp yarns, so a moderate to moderate-high twist might be appropriate.

So, you have your blend, you have your yarn construction, your grist, your twist, and your thickness. Next: sampling. That's right, you need to spin some and measure it. 

The first sampling hurdle is determining singles' size to get the desired plied yarn thickness. The general guideline I use is that, with moderate twist, a 3-ply uses singles that are half the final wraps per inch; and a 2-ply uses singles that are 2/3 the final wraps per inch. I start there, and adjust the singles as needed to get the plied wraps per inch that I need. I have some tips on sizing singles for plying here:

If you are having trouble getting yarn thick enough, you'll either need to spin thicker singles, or add more singles to the ply. If you are having trouble getting yarn thin enough, you'll either need to spin thinner singles, or take some singles out of the ply. I have some other tips on how to get more (or less) out of plied yarn here: 

You use a McMorran Yarn Balance (or the new Yarn Yardage Tool from ) (and there is a DIY one on )That will give you the yards per pound, to compare to the commercial yarn. If the grist is too many yards per pound, your sweater would be lighter than one from the commercial yarn -- it also likely will not be as drapey, something to keep in mind for a Kimono Swing Sweater but less important for a waist-hugging ribbed fitted sweater.  To get the grist lower, a more worsted style of spinning, pinching as you draft, helps make the yarn denser at the same wraps per inch. 

If the grist is too few yards per pound, your sweater would be heavier than one from the commercial yarn -- this could cause stretching of the sweater from its own weight, especially with inelastic fibers like silk and alpaca. To get the grist higher, a more woolen style of spinning, allowing more air in the yarn, helps make the yarn less dense. Another thing to examine is the fiber content -- if it has wool,  perhaps a crimpier wool, or if it is a blend, a larger percentage of wool in the blend will help get more air in the yarn.

Whew! Once you have grist close, it's time to knit a gauge swatch. Remember, we don't want to have to rethink the shaping, so row gauge is as important as stitch gauge. Altering your needle size up or down from the recommended size can help adjust row gauge without overly impacting stitch gauge. Remember that finishing the swatch is an important step here -- it lets the knit stitches wriggle as they can a little so your final fabric is more consistent.

If your row gauge is too low, you may  find a thicker yarn at the same grist helps get you to row gauge. To keep grist the same and increase yarn thickness:

  • use crimpier wool
  • use a woolen prep -- carded batt or rolags
  • don't use commercial wool top, as it is so compressed that it tends to result in more compressed yarns (be sure to wet-finish the yarn before meassuring its grist, so the top can open  up in the finishing)
  • use more of your less dense fibers: fine wool, angora, cashmere
  • use less of your dense fibers: alpaca, llama,  long wools, mohair, silk, rayons
  • use less twist in the singles (so plying also uses less twist, letting the singles be puffier in the final yarn; this is even true in cabled yarns).
  • use a more woolen spinning technique

If your row gauge is too high, you may find a thinner yarn at the same grist or a 2-ply helps reduce it. To keep the same grist and decrease yarn thickness:

  • use less crimpy wool
  • use a worsted prep, or if drum carding, keep all fibers aligned for smooth batts
  • don't use roving, as it randomizes the fibers and keeps air in the yarn unless spun to a very high twist
  • use less of your less dense fibers
  • use more of your more dense fibers
  • use more twist in the singles (and thus have a higher twist final yarn)
  • use a more worsted spinning technique

Whew!  If you can work through all of that, then next you need to figure out how much fiber to start with. The pattern will give you the number  of balls; and should provide the ball weight -- if not, the yarn manufacturer's website, the yarn database or the yarn library on

number of balls * ball weight = total weight of fiber

If the yarn was a blend, or your sampling led to blending, then you need to use your final percentages rather than the ball band's.

So, a sweater calling for a pound of a 50/50 wool/alpaca blend means I would want to have about 9 ouunces each of wool and alpaca.  It would be hard to buy all the fiber up front correctly since you don't know if the blend will spin to the same grist for you, or if you might adjust it. If you had to get it all up front, then I'd recommend that you get about 25% extra of each fiber to have room to make adjustments. And, have some "adjusting fiber" ready in your stash so you can adjust grist if needed.

You can stop spinning when you have the yardage the pattern calls for. Again, look at the number of balls the pattern calls for, and this time, the yards per ball:

number of balls * ball yardage = total yardage

Most patterns, especially if they use multiple colors, will have excess yarn, which means if you spin to that yardage, you will also have some wiggle room.

If you can get your hands on a sample of the yarn the pattern uses then you can see its number of plies, how tightly or loosely it’s spun, and possibly even knit a gauge swatch to see drape and hand of the yarn … All useful if you plan to mimic it.

I prefer to mimic drape, so the garment behaves like it would if the commercial yarn had been used. If you get more ypp in your handspun than the commercial yarn has, your item will be more drapey -- that may be good, or it may be too floppy. If you get fewer ypp, then yours is denser yarn, and your knit item is likely to be stiffer and heavier.

Also, if your ypp is less than the commercial yarn, you will need more fiber by weight than the commercial yarn’s total weight.

Sampling and swatching is important when using handspun. Knitty had a good piece on yarn substitutions in general, with commercial yarns, which also applies here:

I enjoy using my handspun yarn for many handcrafts: knitting, weaving, crochet, Nalbinding, and even embroidery. With an understanding of fiber and grist, I can substitute yarns with great results. Here is an early substitution, handspun 2-ply used to make Fiber Trend's felted clogs pattern (pre-felting):

If you'd rather work things the opposite direction: spin first, then pick what to use the yarn in, see my post on choosing knitting patterns to match handspun yarn: 

© November 1, 2013 by Ask The Bellwether, posted at

1 comment:

Unknown said...

Wonderful article, and I could understand it easily. Thank you. I am a novice spinner, who has been knitting for 60 + years. I like spinning my own yarn when I get around to it. Sometimes too impatient, and too many interruptions
Thanks again,