Spinning thick and thin is one of those abilities that becomes much more difficult as we gain experience. What came naturally to us in our inexperience escapes us as we become more fluid spinners. Letís examine what causes thick and thin and re-learn those steps.
Thick spots in yarn contain more fiber than the thin parts. They also have less twist. This is because it takes more energy to add twist to many fibers than it does to just a few. So, the result is that the thin portions have significantly more twist because the twist is following the path of least resistance.
I find it easier to spin one of my singles in an exaggerated thick and thin, while spinning the second ply very fine to allow it to wrap around the dimensional ply. If you attempt to spin both plies thick and thin often the resulting yarn is uniform because the thick segments of one ply align themselves with the thin ones of the other ply. The uniform ply also acts as a stabilizer to the thick portions which may not have enough twist to stand on their own.
To create the dimensional ply, you have a few choices. If you are spinning from the lock, a handy trick is to only flick open the tips and leave the butt end of the locks unopened. This creates additional tension as you spin because the butt, or shorn, ends tangle with each other a bit before entering into the drafting zone. The additional pull you have to give will draw that section of the yarn tighter, resulting in the thin patch.
When spinning a roving, the thick portion is formed by pushing additional fiber from the drafting zone with the forward hand. The forward hand, or pinching hand normally works to thin out the fibers until they are uniform. In the case of thick and thin, reach further back in the drafting zone every so often and allow some less drafted fiber to advance. This will create the thick patches in the yarn.
Another method I have found to get the thicker bumps into the yarn, is to simply open your front hand and allow the twist to enter the drafting zone in a sudden motion. This allows twist into the fibers that have not been drafted out to a uniform thickness. Resume drafting normally until the thick section begins to wind onto the bobbin, then repeat the step again.
Donít worry if your thick and thin attempts do not immediately give you the desired results. Keep trying, using different methods until you find the one that is right for you. Once you do get the hang of it, be sure to note in your spinning journal all of the necessary details so you can recreate your very own thick and thin yarn.