Editing Yarn (section)

== Weight ==
{{Main|Yarn weight}}

Yarn quantities for handcrafts are usually measured and sold by weight in [[ounce]]s (oz) or [[gram]]s (g). Common sizes include 25g, 50g, and 100g skeins. Some companies also primarily measure in ounces with common sizes being three-ounce, four-ounce, six-ounce, and eight-ounce skeins. Textile measurements are taken at a standard temperature and [[humidity]] because variations in heat and humidity can cause fibers to absorb different amounts of moisture from the air, thus increasing the measured weight of the yarn without adding any fiber material. The actual length of the yarn contained in a ball or skein can vary due to the inherent heaviness of the fibre and the thickness of the strand; for instance, a 50&nbsp;g skein of lace weight mohair may contain several hundred metres, while a 50&nbsp;g skein of bulky wool may contain only 60 metres.

Craft yarn comes in several thicknesses or weights. This is not to be confused with the measurement and weight listed above. The Craft Yarn Council of America promotes a standardized industry system for measuring yarn weight, where weights are numbered from 0 (finest) to 7 (thickest).<ref>{{cite web|title=Standards and Guidelines for Crochet and Knitting – Welcome to the Craft Yarn Council|url=http://www.yarnstandards.com/weight.html|url-status=live|archive-url=https://web.archive.org/web/20070418162310/http://www.yarnstandards.com/weight.html|archive-date=2007-04-18|website=www.yarnstandards.com}}</ref> Each weight can be described by a number and name: Size 0 yarn is called Lace, size 1 is Super Fine, size 2 is Fine, size 3 is Light, size 4 is Medium, size 5 is Bulky, size 6 is Super Bulky, and size 7 is Jumbo.<ref name=":1">{{Cite web|title=Standard Yarn Weight System {{!}} Welcome to the Craft Yarn Council|url=https://www.craftyarncouncil.com/standards/yarn-weight-system|access-date=2021-10-03|website=www.craftyarncouncil.com}}</ref>

Each weight also has several commonly used but unregulated terms associated with it. However, this naming convention is more descriptive than precise; fibre artists disagree about where on the continuum each lies, and the precise relationships between the sizes. These terms include: fingering, sport, double-knit (or DK), [[worsted]], aran (or heavy worsted), bulky, super-bulky, and roving.<ref name=":1" />

Another measurement of yarn weight, often used by weavers, is wraps per inch (WPI). The yarn is wrapped snugly around a ruler and the number of wraps that fit in an inch are counted.

Labels on yarn for handicrafts often include information on [[gauge (knitting)|gauge]], which can also help determine yarn weight. Gauge, known in the UK as tension, is a measurement of how many stitches and rows are produced per inch or per cm on a specified size of knitting needle or crochet hook. The proposed standardization uses a four-by-four inch/ten-by-ten cm knitted stockinette or single crocheted square, with the resultant number of stitches across and rows high made by the suggested tools on the label to determine the gauge.

In Europe, textile engineers often use the unit [[tex (unit)|tex]], which is the weight in grams of a kilometre of yarn, or decitex, which is a finer measurement corresponding to the weight in grams of 10&nbsp;km of yarn. Many other units have been used over time by different industries.