When starting a new project, you will pick up a few key items: the sewing pattern, a spool of thread, and some fabric. And if you're using a sewing machine, you can't forget about the sewing machine needle! Different types of fabric require different sewing machine needles.
Inserting a Sewing Machine Needle
As a first step, remember this: new project, new needle! When you begin a new project, you should always switch your needle to a brand new one. Sewing machine needles are not meant to be used for sewing over and over again, and this can cause skipped stitches and uneven stitches. Needles can be inserted into your sewing machine different ways. Sometimes, needles are inserted where the eye of the needle is facing forwards, and others require the needle to be inserted so that the eye is facing sideways. When you needle's eye (the hole) is facing frontwards, insert your thread from the front towards the back; when it is sideways, always insert from the left to the right. Check your sewing machine manufacturer's instructions for the best method.
When looking at needles, you will see two numbers referenced on the needle. This is the sewing machine needle size, and most sewing machine needles indicate the needle size in both European and American sizing. European needles are measured 60 — 110, and American 8 — 18, so you will often see needles listed is sizes (70/10, 80,/12, 90/14, etc.) It is one size just listed in two different measures. The general rule is the bigger the size number, the bigger the needle! And the thinner the fabric you are using, the smaller the needle size you will need, and vice versa for thicker fabrics (you will need a larger needle).
Universal sewing machine needles are the most common and used for many non-specialty fabrics. If you only sew with basic woven fabrics, then you probably just need to stock your studio with universal needles in various sizes. They usually come in a combo pack with a couple of sizes and these are your best all-purpose sewing machine needles. Just again, remember that the lighter weight your fabric, the smaller needle size you'll want to use.
Stretch needles are probably the second most common needle, and you need to use a stretch/ball point needle for any stretch/knit garment you sew! Stretch needles have a medium ball point that is specially designed to prevent skipped stitches in knit fabrics. Go to use for elastic materials and high stretch knitwear like swim fabric.
When starting to sew any type of denim project, you will need this specialty needle. It is designed to penetrate extra thick fabrics like denim with reduced risk of needle breakage and skipped stitches. In the pack, you will usually find various sizes of denim needles. So if you are using a thicker denim for a jacket, then you will want to use the higher needle size. For denim pants like jeans, you will probably want to use a thinner denim (with maybe a little bit of stretch in it) and you will want to use the smaller needle size. If you denim has a lot of stretch in it, then you may actually have to use a stretch/ball point needle for the seams and then the jeans needle for your topstitching.
If you are sewing with leather, faux/artificial leather, or heavy non-woven synthetics then you will want to use a leather needle. It features a sharp point and edges that cuts the fabric as the needle inserts, this also means that the needle makes a holes in the fabric for the thread so go slow and be careful as you sew because if you need to stitch rip a seam the little holes will still be visible. You may also need to use a Teflon foot so that you metal foot doesn't stick to the fabric and cause skipped stitches.
If you are embroidering on a fabric then you should switch to an embroidery needle. Embroidery needles are designed to work with specialty embroidery threads and have a special scarf/shape that guards against friction allowing you trouble-free embroidery, and decorative stitching.
If you want to add some pizzazz to your project and use metallic thread, then you are going to want to use a metallic thread compatible needle! It has a lengthened eye, a fine shaft, and a sharp point to prevent shredding and breaking of the thread. This needle is also compatible with monofilament.
There are a variety of specialty sewing machine needles not mentioned here including a quilting needle, a topstitch needle, a twin and triple needle. When in doubt, look at the back of the needle pack to see all the compatible fabrics to the needle.
And when you're ready, try your sewing machine on a new project: