Ironically, the thread weight number which is derived from km/kg is used in North America while all US dimensions are still in inches/feet/yards!

For thin, light threads it’s a higher number (50, 60). Weight for thick, heavy threads is a lower number (8, 10, etc). I have all these different spools at home and couldn’t be more confused until I decided to study the problem and learn all the information about thread sizes. Let’s see what we have, and I will explain later what each notation means. And all the threads in that image appear to the naked eye to be about the same size, nevertheless, they could not be more different! In the image below you can see a multitude of symbols that define the thread size. Related post: Sewing thread types and uses And you know what? I was completely confused by all that information. So I decided to look at the threads I have at home and see how they are numbered. If you are using the wrong size thread you may have a jam in the machine, the thread may break or make a “caterpillar”.

When we use a thicker thread for sewing we need to decrease the tension a bit, and when we use a thinner thread for the lightweight fabric we need to increase the tension for the stitches to look nice.

We all know that the thread tension on a sewing machine has to be set depending on the thread size. But the question is – how do we determine what thread is thinner and what thread is thicker?Īlso, if you want to sew nice seams without seam puckering you should use the same size thread in the bobbin or thinner because if you use thicker thread in the bobbin you can get puckers in your seams. Why is it important to know the sewing thread sizes and when we really need to pay attention to the thread size? I think you have read many times this recommendation: “for lightweight fabric use a thinner thread, for heavyweight fabric use a thicker thread”.

Fine pikka silk tera