When I am spinning for a specific project, I want to keep the yarn consistent from beginning to end.
Here are a few things I do to help achieve that goal.
First, I’ll pinch off the yarn near the orifice, and pull a length out (usually 12 – 18 inches) and let it ply back. I keep the tension on both halves consistent, so the ply is balanced. Even if my end yarn is a single or a 3-ply, I want this little 2-ply sample. I tie or tape it to my wheel so I can do quick comparison checks as I am spinning. If my single is consistent, it will make a consistent 2-ply sample.
Next, I use my handy-dandy spinner’s control card. Occasionally, the yarn I am making falls outside the range on the card, but 9 times out of ten it IS on the card.
Again, I pinch the yarn near the orifice and pull some back out (turning the flyer/bobbin backwards if needed). Holding the sample taut, and preventing any of the twist from escaping (i.e. continuing to hold the yarn where I pinched it to pull it off the bobbin) I measure it against the control card. I note the WPI size in my notes, along with the pulley I am using, whether I am using double drive or single drive, fiber content, and any other pertinent info I may want to refer to later.
If I am planning to ply the yarn, I will repeat the ply-back test, folding the single as many times as necessary to give me the number of plies I plan to use. It is a little trickier to keep the tension consistent on any number over 2, but worth it for the sample. I will hold the sample taut and measure it again with the control card, and note WIP size of this plied sample as well. I like to break off this sample and tape it to my notes.
As I begin to spin the yarn for the project, I will stop every 5-10 minutes for the first half hour and pull some yarn back out of the orifice and compare to either the control card, or do a ply back test and compare it to my sample on my wheel. The control card reassures me that I am keeping the diameter within range, and the ply-back sample reassures me that my twist is staying within range. If the samples don’t match, I make the necessary changes, and keep spinning until I pick up the habit for this yarn.
After that first half-hour of spinning, I am usually getting comfortable with the rhythm and grist of the yarn, and can start spacing out my quality-control checks to every 15 minutes, then every 30 minutes. My attention is fickle, and I don’t trust myself to go longer than that without checking. I can spin my habitual yarn all day long and keep it consistent, but if I am working outside that comfort zone, I have to keep tabs on myself, so I don’t wander too far from the goal.
This has been my low-tech solution. I am sure there are more precise or mathematically-correct ways to do this, but I am a lazy spinner at heart, and this gets me the results I need with the least amount of thinking.
*Info from this blog post was also published in an article for the summer 2014 issue of PLY magazine.