To spin a single ply that can stand on its own takes some skill, and I’ll admit it is not usually my favorite endeavor. But sometimes we need a single ply yarn to achieve a desired result, or just to test our own skills.
Single ply yarn is very useful in weaving as warp yarn. It can also be used to create a blanket stitch edge or embroidery detail on knitted items, or if you want an exquisitely light and airy lace shawl. Be sure you know what your intended use for the yarn is before you begin to spin. If it is to be knit, have the needles you intend to use on hand to check the size of the yarn against. It the yarn is to be warp for weaving, take a good look at the loom you will use, and keep in mind the ends per inch requirement of the weaving project.
The key to spinning a successful single yarn is to get just the right amount of twist. If there is too much the yarn will kink and you will always be fighting “live” twist. If there is too little twist, the yarn will not be strong enough to be useful.
To spin singles requires patience and a bit of restraint. A ruler will also help to maintain consistency. Pre-draft your fiber as much as possible, being careful not to make it thinner than your desired finished yarn.
Set your wheel to a tension that will take up readily without having to pull too much on the yarn. If your wheel has interchangeable whorls, this is the time to get the big ones out. A larger whorl will have fewer turns per treadle than a smaller one.
As you spin, stop periodically and wind the yarn around the ruler to see how many times the yarn can be wrapped around the ruler within a one inch space. This is know as wraps per inch, or often abbreviated as wpi. Another characteristic of the yarn that can be checked to maintain consistency is the twists per inch, or tpi. To check the twist, grasp both ends of one inch of spun yarn (without severing it from your work of course) and untwist it. The number of twists per inch is how many times you untwist until you have straight fiber. As soon as you let go of the yarn after checking the twist, it will spring back to its twisted form. A quick trick to check for knitting size is to be sure that two thicknesses of the yarn is not larger than the diameter of the needle you intend to knit it on.
Once you have spun the single yarn, wind it off and tie it using a figure eight in four places. Be sure to give the yarn a good soak to allow the twist to even itself throughout the skein. For warp yarn, to reduce the twist energy, dry it under tension by hanging it with a weight tied to the bottom of the skein. A small jug of water that has a handle works great for this.