Most home sewing and embroidery machines use flat shank needles (the shank is rounded with one flat side), and commercial machines use round shank needles.
Take a new needle every 8 hours of embroidery. A dull or burred needle can cause snags and puckering, so if you experience stitching problems, try to replace the needle. A small-eye may create tension problems, although it is not always the best choice to use a large needle to avoid thread fraying and breakage. The larger needle may produce unsightly holes in the fabric, or even cut the fabric, creating gaps between the embroidery areas.
To test whether your needle creates too much tension on the thread or not, cut a piece of thread about 12 inches long and thread it through the needle. Hold the thread vertically and fairly taut. Then, from the top, spin the needle. It should slip down the thread. If it doesn’t, you need a needle with larger eye.
Selecting a suitable needle should be based on the weight & type of fabric, and the weight & type of thread you are going to use. The heavier the fabric and denser the weave, the larger the needle will need to be, and vice versa.
The most commonly used needle sizes in machine embroidery (in both European & American numbering systems) are 65/9, 70/10, 75/11, 80/12, 90/14. Machine embroidery needles have a slightly larger eye and groove in the shank than sewing needles, to protect embroidery thread from shredding and/or breaking.Needles are available in many types - Sharps, Wedge (cutting) Points, Ball Points & Metallics:Sharp point is good for most woven fabrics that won't unravel. Sharps cut through the fibers, and deliver the thread with less push and pull on the fabric.
Ball point is used with knits and other stretchy fabrics, when it's important to avoid cutting the goods by needle penetration. The rounded points will cause the needle to slip between the fabric threads to prevent cutting the fabric and causing it to unravel.
Wedge points are for leather, vinyl and other heavy, super dense materials. These needles are for fabrics which are not woven, as they make a small slit rather than a hole. The wrong needle on leather would cut the design out.
Fortunately, needle manufacturers have also designed marvelous needles for specialty embroidery thread
- like metallic, glitter and other delicate exotic fibers. Specialty needles (like Sullivan's Metafil, Madeira's Metallic, Schmetz Metallica etc..) have larger coated eyes and deeper scarfs to handle the thread more easily.
Please be sure to test-stitch your designs with the type of needle you're going to use on final projects. There are exceptions to the rules, and it's always a good idea test the needle and other components, before using them on final projects.