Lace weight yarn is a type of yarn that is very fine and delicate, almost resembling sewing thread. As its name implies, this yarn is most often used to knit or crochet garments or accessories that feature some kind of lacy motif. Due to the complexity of many lace patterns and the difficulty of handling the very thin strands typical of this yarn, it is not always the best yarn weight choice for a beginning knitter or crocheter, although lace patterns for beginners do exist.
Yarn weight is determined not by weighing a ball of yarn, but by examining the thickness of a single piece of yarn. The standard yarn weight system puts all very fine yarn weights into the "lace weight" category, which includes thread, cobweb, and true lace weight yarn, the thickest of the three. Fingering weight yarn, which is the yarn most often used to make socks, is thicker than lace and is classified as "superfine" using the same standardized system. The "light" weight category is for sport weight yarn, while the "fine" category is for double knitting (DK) weight yarn, and the "medium" category includes the two most popular weights for most knitters and crocheters, worsted and aran. Finally, there are the thickest yarn weights, bulky and super bulky, each of which have their own weight category.
Lace weight yarn is often used to make lightweight shawls, wraps, and scarves with complicated and ornate lace motifs that resemble leaves, flowers, insects, feathers, diamonds, chevrons, or other geometric shapes. It can also be used to knit or crochet hats, gloves, or sweaters. Sweaters made with lace weight are more uncommon, however, because the thinness of the yarn makes completing large projects very time-consuming.
When lace weight yarn is knit or crocheted, the resulting fabric is usually very thin, with an airy, gossamer-like texture. Most yarns of this type knit at a gauge of eight or more stitches per one inch (2.54 cm) of knitted or crocheted fabric, and wrap around a ruler 18 times within an inch. The needle or hook size recommended by most lace weight yarn labels will probably be very small, between one and a half and two and a quarter millimeters in diameter. However, most lace patterns recommend that the fiber artist use a much larger needle or hook size so that the lace really stands out.
Many fiber artists find lace weight yarn to be fussy and difficult to handle. Depending on the fiber content of the yarn and how much it is pulled or manipulated, it is possible for the yarn to break during knitting or crocheting, or during the blocking process which often follows the crafting of a lace shawl. However, the fineness of lace weight makes it a good yarn choice for crafting during warmer weather when knitting or crocheting with heavier weight yarns becomes hot and uncomfortable. Additionally, lace weight is very economical, as a 50 or 100 gram ball of lace weight yarn has more yardage in it than a ball of worsted weight yarn of comparable size and weight.