Yarn count is enormously interesting to beginning weavers but is also very complicated. What is so confusing is that this system was invented in the nineteenth century, and each fiber, such as cotton, linen, wool, or silk has its own specific method for determining the count. I explained yarn count in a previous post quite a long time ago. Please click this LINK to that post for the explanation.
Here’s how you can find the yards per pound when you know the yarn count (explained in the post mentioned above at the link given). The example here shows how to know the ypp (yards per pound) of 5/3 cotton.
A plied yarn is a yarn that is made up of more than one strand. For example, if you folded a one-ply yarn on itself, you would get a 2-ply yarn that would still weigh the same amount—for example, one pound—and would be half as long.
This illustration shows a 3-ply yarn. Diagonal lines can clearly be seen on yarns that are plied. If you look closely at the cut end in this illustration, you can see that there are 3 plies in the yarn, or 3 strands. Another way to count the plies is to untwist the end of a yarn and count the strands that can easily be seen.
By knowing the number of yards per pound of a yarn you can tell whether the yarn is fat or thin. If there are many yards in one pound the yarn is thinner than if there are only a few yards in a pound.
Summary: How to know if a yarn is fat or thin
The fraction given for a yarn tells if it is a thicker or thinner yarn by indicating the number of yards per pound. If cotton has a base count of 840 ypp for one strand, you can see that by looking at the counts only, 10/2 cotton (ten times the base count or 10 x 840, or 8400) has more yards per pound and, therefore is finer than 5/2 cotton (5 x 840 or 4200). Finally, by dividing the count’s ypp by the number of plies you get the yards per pound for 10/2 cotton as 4,200 ypp. The 5/2 cotton has only 2,100 yards in a pound (4 x 840 = 4,200 divided by 2 = 2,100 ypp).
Otherwise, look at the label for the yards per pound. Thinner yarns have more yards per pound than thicker ones. My mentor, Helen Pope told me thinner yarns are cheaper than fatter ones because you get more yards per pound.
In your weaving life, you’ll become familiar with some types of yarns and will remember some fractions and what they mean.
For more information, see my first book, Winding a Warp & Using a Paddle HERE on pages 91 and 113-116.
When the Yarn Balance and yarn count differ.