I had spun this sparkly blue roving (Wool, Silk, Nylon, silver fibers) but the resulting yarn was too bulky to knit in-the-round for my vessels. I didn't want to make it even thicker by spinning it again with a second plying yarn, so I tried a tip I saw posted in my Facebook drop spindle group. I spun it again and plied it with a black Perle cotton thread (hope you can see it) instead of a second yarn. A thread with more contrast would have been pretty, the color possibilities are endless. The thickness is even better now, and I know I can knit with it. Practicing and experimenting here!