Wraps per inch
Right now I'm working on a stripey linen tank in Sparrow. I'm making up the pattern as I go, loosely following some sketches and stitch counts. Since I'm an indecisive person by nature, this project isn't always the one I want to reach for. Sometimes I just want to follow a pattern and not have to make a single choice. [Let's not talk about how long it takes me to make all the choices necessary to chose a pattern where I won't have to make choices.]
While I still haven't made up my mind as to what I'm going to cast on, I'm [fairly] certain this is the yarn I want to work with, since it's both a different fiber and weight than Sparrow. It's a farm spun wool that I pick up while visiting my mom in Roanoke some time back.
This wool gives me the opportunity to share a tool with you: w[raps]p[er]i[nch]. By determining a yarn's wpi, you can find its weight. To do so you simply wrap the yarn around a ruler, using minimal tension, and count the number of wraps that fit in a one inch span. Simple.