This clever little tool  will help the spinner to create consistency in a range of yarns as well as checking the grist of the yarn.  The protractor helps to determine the angle of the twist to ensure a perfectly finished yarn. It also has a handy inch / centimetre rule too.
 
If you need to know the thickness that the single yarn needs to be to achieve your chosen finished thickness then you may like to take a look at our more comprehensive Spinners Control Tool  which is also listed in our shop.  https://www.thespinningbarn.co.uk/product-page/spinners-control-tool-1