These WPI (Wraps per Inch) Rulers are made from cherry wood and isare used to identify the gauge of a yarn.
Wraps per inch (WPI) is a way to measure the thickness of a yarn. This tool is used by spinners, but is also helpful for knitters and crocheters to determine the weight of the yarn and what the approximate gauge will be. This guide also has lines on the back to measure your yarn against, including lace, fingering, sport, DK, worsted, bulky and super bulky.
