I’ve been thinking a lot about what all those ways that yarn manufacturers, including myself, categorize the yarn. There are so many ways of speaking about the size of the yarn. The standard yarn weight information is set up in a table with discreet squares. But I’ve been studying this lately and I’ve noticed that there is overlap, a lot of overlap among the yarn weights. So it seems to me that this is really a continuum. Just look at the info about YPP, yards per pound, the overlap here is really large. Why is that? It has to do with the spinning process.
Was it spun in a woolen way with lots of air and softly spongy and so it has a bigger diameter? Or was it spun in a worsted way which compacts the fibers and aligns them all in one direction and so it appears thinnner. These two yarns could have the same YPP but a different grist or appearance and they will behave very differently. So use these as a guide, but the ultimate test is your own swatch. These two yarns were both supposed to be a DK weight. But the diameter is SOOOOO different. They knit up differently too. The green one knits like a lace weight yarn. It is our Heritage BFL yarn. And the turquoise yarn is Fingal’s and truly knits like a DK yarn. It is also made with BFL wool and both were made at the same mill. Go figure!!
This really comes into play when you are wanting to make that special sweater. You are wanting to use yarn from your stash, not go out and buy the yarn that the designer used. Or maybe that yarn isn’t available anywhere near you. This is when those standard yarn weights become important. And even more important than that, is to knit up a swatch. Not only a stockinette swatch but also a swatch in pattern.
But is a swatch important when it is for a garment that doesn’t fit your body, like a shawl or a cowl? Well, I think getting the gauge close is important so that the stitches look the same. You may not need to get it “exactly” right if it isn’t going to “fit” your body. What is important to do is to check the size of the finished project, because many times the photographs used in the pattern, may be on a mannequin and not a person. It may be made for an extremely small or large person, someone whose body is vastly different than yours. Sometimes making a swatch seems like wasting your time and a waste of yarn. You will probably only need 25-50 yards for a swatch. It will reduce the chance that you would need to frog your project. I think it is important to make sure that the stitches look right. You may be a looser knitter than the designer or vice versa. So changing your needle size will be just what you need to get your swatch to look like the picture. Those are important questions to answer and it is worth the time to figure this out before you jump into your garment.