Most probably everyone knows that in the world of yarns there are thin yarns, thicker yarns, and really thick yarns. From wafer-thin to finger-thick, the range in yarn shops and online shops is quite large. There is always the right yarn for every project.
Whether a yarn is considered thick or thin - just like in real life - is ultimately relative. For this reason, yarns are grouped together according to their thicknesses into categories. This is particularly helpful if you want to knit a specific piece and need the yarn weight given in the pattern. Needless to mention here that gauge is also important when following a pattern …
Other Countries, Other Customs
If you now think “Great, then everything is clear!”, we must take the wind out of your sails a bit first. Depending on the origin of the yarn, the designations are quite different. Anyone who is familiar with our blogs knows that we are happy to help you out with a bit of background knowledge. And so, at the end of this article, we hope you will be able to read different yarn labels and patterns and find your way around the tangle of designations.
Yardage and Gauge
In German-speaking countries, it is common to indicate the yardage of the yarn on the label. This means the number of metres (yards) of yarn that form a ball or hank. On the label you will see something like "yardage 300 m (328 yds) /100 g". With a bit of experience, you will have a rough idea of which needle size you need with this yarn and what the stitch pattern will look like with it.
However, different fibres also have different specific weights. As a rule, cotton yarn is heavier than cashmere and with the same weight and yardage a cashmere yarn will be significantly thicker than a cotton one.
The quality of the yarn is also decisive for how the stitches will look in the end: With a tightly twisted yarn (e.g. sock yarn) there is less leeway in terms of needle size than one that is very airy and fluffy: the latter can be knitted with a smaller needle size to get a firmer knitted fabric, or with thicker needles to get a looser fabric with a nice stitch structure.
For this reason, information about the length of a yarn should always include information about the needle size to be used and the gauge: this tells you how many stitches and how many rows of yarn make up a small piece usually of 4” x 4” (10 x 10 cm).
Recently, however, yarn manufacturers and designers from German-speaking countries also often use international designations for the thickness of yarns.
If you browse through Ravelry and look at English-language knitting patterns, you have certainly stumbled across a number of terms for different yarns: Cobweb, Lace, Fingering, Sport, Sock, Baby, DK (double knit), Worsted, Aran, Chunky, Bulky, and Jumbo.
They all refer to the "yarn weight". However, this is not about the weight of the yarn as such but rather about its thickness and is based on gauge. While with a cobweb or lace weight yarn you need well over 30 stitches to get a width of 4” (10 cm) in stockinette stitch, with a jumbo weight, you will need just 6 stitches or less.
WPI – Wraps per Inch
Wraps per inch is exactly what it sounds like: a strand of yarn wrapped several times around a ruler until one inch (that's 2.54 cm) is covered. The higher the number, the thinner the yarn. Again, comparing the two extremes: Lace is 30 to 40 WPI, Jumbo 1 to 4 WPI.
This is another way of classifying yarns. It refers to the number of individual strands that are twisted together to make a yarn. The twist is usually given for sock yarns (4-ply, 6-ply or 8-ply) to describe the stability of the yarn. 1, 2 and 3 ply are more commonly used to describe fine lace yarns. However, it’s important to note that ply does not necessarily correspond with yarn weight or thickness. Some very chunky yarns are only two-ply (that is, they have two, thick strands). On the other hand, some multi-ply yarns are quite thin.
Ply was commonly used at a time when mainly virgin wool was processed. This meant that the individual strands were mostly the same and the different twists could be easily compared with one another. With increasing variety of materials and more and more technical possibilities to produce yarns, ply has lost a lot of its meaningfulness.
Standard Yarn Weight System
The US Craft Yarn Council (CYC) - an association of companies in the yarn industry - developed a system in the 1980s that relates yarn size, gauge and needle size. This results in a numbering system ranging from 0 (lace) to 7 (jumbo). The corresponding symbols are balls of yarn with the numbers inside. These can be found on the labels of (American) yarns.
Incidentally, in our online shop you can choose to display the yarns sorted according to the CYC classification. If you prefer, you can have it displayed according to yardage, gauge or recommended needle size!
Lots of Overlapping
If you look at tables on the internet or in knitting books in which the different yarn classifications are listed side by side, you will quickly notice that there is some overlap. The knitting gauges given – be it on labels or in the CYC – can only ever be used as a guide. Everyone knits differently, some looser, some tighter.
We have put together a table for you here, where you can see the classification of yarn according to weight. Please don't be surprised if you see different numbers elsewhere - the classifications always seem to be a little different everywhere.
This should give you a rough idea and it will be helpful when deciding on what yarn to use for your next project!