Awesome Question from Tom About Yarn Weights

"Can you explain for us un seasoned MK'ers what the coned yarn weights are in relation to the Yarn Council chart? What is a Yarn Council "1" equal to on coned yarns? Example: 2/10, 5/12 and etc."


The top number is how many strands or plies are twisted to make that particular yarn and the bottom number is a measurement of thickness - how much length you get in a certain weight of yarn.  Therefore, the bigger the bottom number, the skinnier the strand.


This isn't entirely precise because some fibers weigh more than others for the same thickness and yardage.  It gives you a starting place, though!


I have done some research on this issue and am not any kind of expert. I get befuddled once they start talking about S and Z twists and tiny cotton fibers.  Maybe a person from the textile industry can weigh in and help us.  It does seem to me that weavers can use yarns that behave badly for knitters. 


I do have a lot of experience, though, that is, I've struggled for years to make very nice knitted items, so I have a rule-of-thumb method for figuring out the weight (thickness) of coned yarn when all I have is that marking.  What I do is divide the bottom number by the top number, which I realize is backwards for fractions, to get a number to help me classify the yarn.  For instance, with a 1/12 or a 2/24, I get "12" which to me means it's lace weight.  If I get anywhere from a 9 to a 12, I'll call it a lace weight, but I know a 12 is a lot thinner than a 9.


If I divide and get about a six, with a 1/6, 2/12, 3/18, that's about fingering weight and is just wonderful for the standard machine.  I figure 6 is right in the middle of the fingering group and would say that anything from about 5-8 goes in that family.


It follows from this that 2 strands of a "12" gives you a "6."  For instance, two strands of 2/24 gives you 4/24.


I hardly ever buy much thicker yarn on cones, and if I do, it seems like the seller has described the thickness.  


I knit a lot of swatches.  It's not just to get gauge - it's to feel the swatches and wash the swatches and make decisions about how best to use the yarn.  I think about whether the fabric is stable, not warpy or shapeless.  I want to make sure the fabric feels good, and isn't too dense or loose.  And of course, I use swatches to help decide about textures and color combinations.