Lace yarns are extrafine yarns included in group 0, according to the Standard Yarn Weight System that classifies yarns by weight. These ultrafine yarns can be used with 1.25-2.25-mm knitting needles or with a 2.25-mm crochet hook. Normally, we recommend using larger needles —between 3-3.5-mm— to achieve defined lace and light and airy fabrics. One ball of 100 grams of (2 ply) lace weight yarn can consist of around 800 meters. Another of its characteristics is its high WPI (Wraps per Inch) count of-40+.