How to work out ply of wool

I have lots of half used balls of wool without the bands, it is sometimes quite hard to know what ply they are, any advice about working this out. I know there is a method where you wind wool around needles but I can’t find this online. Also I suppose I could knit them up to find out their ply? Thanks

Welcome to Knitting Help!
Here’s an explanation of wraps per inch which will give you at least an estimate of the weight yarn that you have. This tablegives an idea of how that translates into yarn types. Of course, knitting up a sample will certainly help because you can measure stitches per inch on a particular set of needles.

Hi jandraper. Here’sanother article that has a wpi (wraps per inch) table at the bottom and explains the equivalants in yarn weights - like 4 ply = fingering/sock, and so forth.