What are singles? Jillian Moreno defines singles as yarn that will be used as is, in its unplied state, and a single is a yarn that is plied after it is spun.
Pro: No plying. Great for color effects such as gradient yarns and long striping sequences.
Con: Knitted fabrics created with singles tend to bias. Singles yarns pill more.
Tip: The key to sound singles is adding just the right amount of twist. Add enough twist to hold the yarn together while keeping the twist angle low enough so the yarn won’t bias in knitted fabric. Fulling singles during finishing leads to better resistance to wear.