Quote from book “By changing the hook size and thread weight, the same edging can be used for a variety of items. The delicate lacy edgings are achieved by working with a very fine thread, while the more durable edgings are worked with coarser thread.” It gives a table suggesting thread weights and hook sizes for a variety of items from handkerchiefs to bed linens to baby items, along with this is a photo of the same edging worked in 5 different thread weights to give a visual reference.