Chain plying, also known as Navajo plying, is a plying method that uses one single to get a three-ply. This is unlike the traditional three-ply, which requires three separate threads. Using a wheel, a traditional three-ply requires four bobbins--three for the singles and one for the plied yarn. A chain ply, on the other hand, only requires two bobbins--one for the singles and one for the finished yarn. If you wind off your singles onto a storage bobbin or into a ball or cake, you can go from singles to finished yarn with only one bobbin. Plus, since you are only juggling one thread instead of three, you never have to worry about extra singles on one or two of the bobbins--you can ply every inch of your single into the finished yarn.
Great! So how do we do it? Well, chain plying is basically just making a large crochet chain and then adding twist. If you can already make a crochet chain, you can chain ply! You're just going to be using your hands instead of a crochet hook (though I suppose you could use a big crochet hook if you really wanted). If crochet is a foreign tongue, that's all right. Just follow the tutorial below, and you'll be chain plying everything in sight in no time.
Chain plying tutorial
The first step is to make a loop at the beginning of your single.
If you're okay with a tiny knot at the beginning of the yarn, you can start your chain ply with a simple slipknot. The slipknot is unlikely to make it into whatever you make with the yarn anyway, and you can always snip that bit off later. If you are diametrically opposed to knots of any kind (some people are, and that's OK), then just take about a foot of yarn and fold it into thirds like so:
I've made a small loop here so you can see, but you really want a much bigger loop--big enough to reach both your hands in. Now, lay the yarn over the leader, loop toward you. Pinch the yarn a little below the leader where you'll still have a loop big enough to put your hand in and add some twist. You want enough to hold your yarn to the leader so it won't come apart.
With your non-dominant hand (so your left if you're a righty like me), hold the yarn just in front of the orifice to control the twist. This hand will feed the plied yarn onto the bobbin just like with any other sort of plying or spinning a single.
With your dominant hand, you're going to hold the single as in the picture below:
Spread your thumb and forefinger apart to hold open the working loop (green). Keep the working end of the single (blue) out of the way with your pinky finger. With your middle or ring finger, you're going to scoop up the working yarn just ahead of your pinky to create the next loop. Bring your finger over the top of the strand, hook it around your finger and draw it down through the loop. As you scoop up the working yarn, allow your thumb and forefinger to close, pulling your whole hand through the loop. Make sure your pinkie finger holding the working yarn is loose enough for the single to slip through.
Once you've pulled your hand through the loop, you'll have a loop of yarn on your middle or ring finger (which you can transfer to your forefinger) and the working yarn held in your pinkie like so:
Poke your thumb into the loop next to your forefinger and then open your hand, holding the yarn just like you were before.
Continue in this manner, holding the loop open, scooping up yarn for the next loop and drawing it through the working loop until you're finished plying. When you need to pause to switch hooks on the flyer, hold the yarn just like above, with your thumb and forefinger holding the loop open. If you need to stop plying altogether (to get up or finish later), you can just hook the loop over something handy (I use the tension knob on the side of the wheel) to keep it open. Then when you return, poke your thumb and forefinger into the loop and grab the working yarn with your pinkie.
While you are still getting the hang of things, the most important thing to remember is to treadle slowly. That will give you enough time to get into the rhythm of grabbing the yarn and pulling it through. It can be super annoying to have to pick everything apart to find the loop again if you drop it or the yarn breaks.
If the yarn breaks: First of all, don't panic. Stop treadling and untwist the yarn enough to pull out the free end of the working single. You have two options: If you can see the other broken end of the single, you can tie them back together. If you're anti-knot or you can't see the free end and your single is too weak or fuzzy to go looking for it, just lay the free end next to the loop and add some twist to hold it in place, making sure to hold the loop open. Then continue to pull through new loops as usual.
And that's it! If you're anything like me, you'll struggle to refrain from chain plying every single you spin. Not that there would be anything wrong with that.