In England and some parts of Europe, knitters refer to what Americans call yarn as "wool," a practice that can cause confusion when discussing the craft internationally. Most skeins, hanks, balls or cakes of wool or yarn for knitting come with a label or "ball band" indicating critical information about the product. This information ranges from how to care for the fibre to the fibre content itself. These labels are important to knitters, who use it to determine the sorts of projects for which the yarn is suitable and which size needle to use with the yarn.
Find the yarn weight classification. The Craft Yarn Council has a standardised system of yarn weights that many companies have adopted for their labels. This is indicated with a small graphic of a skein of yarn, with a number on a black square. These numbers range from zero to six, with zero being the lightest weight yarn. However, some companies do not include this information, so knitters must rely on the gauge to determine the weight of the yarn.
Examine the gauge information. Nearly all yarns have gauge listed on the yarn label. Some yarn labels have a graphic depicting a square, 4-inch-by-4-inch swatch, with a knitting needle laid diagonally across the square. This tells knitters how many stitches per inch a yarn will get on a range of two to three needle sizes. The larger the needle listed, the heavier the yarn.
Read the fibre content. Most commercially produced wool yarn labels simply state that they are 100 per cent wool, without any further information on the sheep's breed, as these yarns are blended from many types of fleeces. Blends with other fibres should be listed in this section. A label that says "virgin wool" means it has never been used for another product.
Look at the yarn care symbols. While many yarns will simply print "hand wash only" on their yarn labels, a few companies use universal care symbols on their products. These symbols indicate whether to wash and dry by hand or machine, the temperature of the water, bleaching, ironing and dry cleaning instructions.