Using the right needle for your project is important. If you use the wrong needle, you might end up with messed up fabric, dropped stitches or even have the thread break off when you’re in the middle of sewing a seam. In the absolute worst case, you can blow the timing to your machine, which requires a trip to the shop to fix.
Learn which model of needle your sewing machine needs. The majority of machines take one of two types of needle.
The big difference between these needles it that one has a flat part to the shank, and the other has a totally cylindrical shank. Your sewing machine’s manual will tell you what kind of needle it takes.
Now consider the point of your needle. No, not its purpose, the sharp bit at the end. Different needles have different points, according to their function.
Universal – good for general usage on most woven fabrics.
Ball point – sometimes labelled as “jersey”. These are for sewing knit fabrics. I’d use this for rib knits and velour.
Stretch – also meant for knits, but intended for really stretchy, elastic fabrics. I’d use these for Spandex.
Sharps – sometimes labelled “microtex”. These needles are very thin and are used for decorative top-stitching, or for when you’re sewing something that won’t forgive needle holes easily, if at all – such as metallic coated fabrics and lamé.
Leather – These needles have a triangular cross section and are built to “punch” their way through leather and suede. Do NOT try using these on regular fabrics. They will tear the fibers and weaken the seam.
Jean – A modified ball-point needle, slightly heavier in weight to get through thick denim. I’ve used these when sewing duck for corsets, although I’ve used universal needles without any problem, too.
Once upon a time – shamefully recently, in fact – I tried skipping out on using ball point needles on a stretch fabric, because I didn’t have time to go out and get ball-point needles and I paid for it. The machine dropped stitches every couple of inches and the thread snapped almost as often. I finally realized I wasn’t doing myself any favors and apologized to my friend that I’d need another day to do those alterations to her dress, so I could buy the right needles, which I should have done in the first place.
Along with the tip, sewing machine needles are packaged with a number that gives an idea as to how heavy a fabric they can sew. Somewhere on the package, you’ll see a weird looking fraction – like 70/10 or 80/12. The first number is the size of the needle according to the Singer system. The second number is the size of the needle according to the metric system – because we can never keep things simple in this world and there are two classification systems in use. The higher those numbers, the heavier (and thicker) the needle. The heaviest I’ve ever seen for sale for home use was 110/18. There are other numbers on the needle package, but that’s really the only one you need to worry about when you’re just starting out. When in doubt, start with a 70/10 needle, as that’s a good default size. The heaviest I’ve ever resorted to was a 90/14 when I was doing some industrial-strength corsetry.
Here’s a guide on how to read Schmetz needle packaging.
Always, and I mean always, start a fresh project with a fresh needle in your machine. Should you hit a pin or a corset steel while sewing, immediately replace the needle – assuming it didn’t break outright. Even if you think the needle looks and feels fine, you want to replace it after it strikes a hard surface. A bad needle can ruin your fabric, so why risk it?