Lace weight is the thinnest, lightest type of yarn. It’s used mostly to knit lace shawls and scarves. To get the open lace effect, use a larger needle size.
Fine yarn includes sport and baby weight yarn. This is a versatile yarn that’s great for just about anything: cardigans, sweaters, hats, socks, you name it.
21-24 sts = 4" in st st US 5-7 (3.75-4.5mm) needle
DK weight and light worsted yarns fall into this category. These yarns are just a slightly thicker than fine yarns and a slightly thinner than medium yarns.
Super bulky yarns are the ultimate in instant gratification. At 6-11 stitches to four inches, you can easily finish a hat in just a few hours. These yarns are usually single ply and super warm on account of their bulk.