What is plied yarn?

What is Plied Yarn?

As we continue our look at yarn construction types, let’s talk first about plied yarn. Plied yarn has come to mean yarn created by twisting unspun fiber under tension. The resulting strand is a single.  Twisting makes the fiber strong enough to be used without breaking when you pull on it.  The greater the twist,  the stronger the yarn, but there is a limit to how much twist a yarn can have and still behave.  

Why do they ply yarn?

Too much twist and a single strand of yarn begins to kink up on itself. When another single strand is twisted with the first single, in the opposite direction, they balance one another and create a strong yarn that’s not over-twisted.  Two strands together make a 2-ply yarn.  The addition of a third strand makes a 3-ply yarn and so forth. A plied yarn is not only stronger, but more uniform along their length.. 

Are 4-ply yarns thicker than 2-ply yarns?

Yarn weight and number of plies can be a very confusing topic as it is tempting to imagine that a 2 ply yarn is thinner than a 4 ply yarn and that a 4 ply yarn is thinner than an 8 ply yarn, and so forth, but that isn’t always the case. You can have almost any number of plies in yarn of any gauge, from fingering to super bulky. Rowan Big Big Wool has 2 plies while worsted weight Manos Alegria Grande has 4 plies.  Always look at the recommended gauge on the yarn label to know what gauge the yarn actually is.  

Why do the number of plies in a yarn matter?

The number of plies not only impact the yarn’s strength, but the way the yarns behave in your knitted fabric.  Singles, 2-ply, 3-three ply, and 4-ply yarns each have their own unique characteristics and create a wide variety of surface textures and stitch definition.  

Single Ply yarns 

Single ply yarns are soft and lovely, and can make wonderful fabric.  Most Noro yarns are singles, as are many of our favorite yarns like Juniper Moon Moonshine and Manos Maxima. They knit up into a deliciously smooshy fabric with a very slightly rustic texture. Depending on the fiber content and the amount of twist, single ply yarns can create a bit of bias in stockinette  fabric.  In wool and wool blend yarns, blocking eliminates much of that bias, so it is always a good idea to knit a swatch and give it a nice steam to make sure.  

As a side note, the term plied derives from the French plier, which means to fold because originally, the single spun strand was folded back against itself to make a two-ply yarn. If you’re a language geek like me, you’ll note that a single ply yarn is a misnomer since it hasn’t been plied at all, only twisted.  But the term single-ply has come to refer to any yarn that is not plied at all.  

Two ply yarns

Two singles twisted against one another create a 2-ply yarn that is stronger and more balanced than a single.  Examples of 2-py yarn include, Rowan Norwegian Wool by Arne and Carlos, Feederbrook Entropy, and Kelbourne Woolens Scout, which are all dk weight yarns, Rowan Big Big Wool which is a jumbo weight yarn, and Tea Time Fibers Darjeeling, which is fingering weight. So you see that the number of plies is not at all related to the yarn’s gauge.

A 2-ply yarn will create a subtle texture in your knitted fabric.  The extent to which that texture exists depends on the amount of twist and other decisions made during the spinning process.  Again, blocking your swatch will give you the truest indication of how your fabric will actually look in your finished garment.  

Three ply yarns

If instead of just two singles, three singles are twisted together, you have a 3-ply yarn.  That third ply makes the yarn perfectly balanced and round with stitches that sit perfectly symmetrically in your knitted fabric and display your fancy stitch work to great advantage.  Examples of 3-py yarns include Rowan Pure Wool Superwash Worsted, Berroco Vintage, and  Kim Dyes Yarn Shortbread DK.

These are your workhorse yarns that wear well and look great for a long time.

Four ply yarns and more.  

The  more plies you add, the stronger the yarn.  Sturdy and hardwearing, Manos Alegria Grande is an example of a 4-ply worsted yarn, but you can also have 4 ply fingering weight yarn, such as the sturdy 4-ply Tea Time Fibers Morning Breakfast that Jenny May prefers for socks.  

Additional plies are often how yarns are made thicker as well.  Juniper Moon Santa Cruz is a 4 ply yarn, while its big sister, La Pampa is a bulky yarn with 12 plies.  

Remember that this is only an overview of plied yarns and how they impact your fabric.  The fibers used, the preparation of the fibers, the amount of twist at every stage all impact the resulting yarn and how it will appear in your fabric.  

It is always a good idea to swatch whatever yarn you are considering. Swatch it in pattern, and give it a nice little steaming to see how it will ultimately look.  

More resources and information

If you are interested in more details of how ply impacts fabric, here are two excellent resources.  

Jilian Moreno, spinner, knitter, teacher, and blogger, wrote a wonderful guest post The Why of Ply, which I encourage you to read here. 

Spinner, knitter, author, and all around yarn guru, Clara Parkes shares a wealth of knowledge about spinning and yarn in general in her book, The Knitters Book of Yarn, published by Potter Craft and available on the secondary market.