- The American system uses 8 to 19, 8 being a fine needle and 19 being a thick heavy needle.
- European sizes range from 60 to 120, 60 being a fine needle and 120 being a thick heavy needle.
- Think of a fine sheer window curtain. You will need a fine needle such as a 8/60 needle. Using a 19/120 would leave holes in the fabric.
- Now let's look at heavy upholstery fabric. If you were to try and sew through upholstery fabric with a 8/60 needle, it would bend or break. Using a 19/120 provides a needle strong enough to penetrate the fabric and carry a thread strong enough for this type of fabric.
- Now let's look at a combination You have a lightweight fabric but you want to do a heavy topstitching detail with heavy thread. Normally the heavy thread would call for you to use a heavy needle such as a 120/19, but that would leave holes in your fabric. Now you would experiment with a needle that falls somewhere in the middle such as an 80/12.
You may find a needle size listed as 90/14 or 14/90. The order of the numbers does not effect the size.