just remember the thinner the thread, the weaker the thread!
Bottom line is not the only one you can use, Aurifil also had a bobbin weight, as does YLI soft touch...and Masterpiece! LOVE them all...they are great for paper piecing, but since you tinier stitches when PPing, you don't mind the thread being thinner...when piecing though, one must remember, the higher the the number the less the weight...the less weight means it is easier to break!