Universal
Universal needles are a basic, standard needle. They work best on medium-weighted, woven fabric and can cause problems when sewing heavier or specialty fabrics. The needle is long enough for the needle and bobbin to almost always meet, and the point is slightly rounded. Universal needles come in every size.
Sharp and Microtex
Sharp and microtex needles have a narrower shaft and a sharper point than the universal needle. Use them when sewing finely woven fabrics such as silk, microfiber, chintz and faux leather. Because of the acute point of these needles, you can also use them in place of specialty needles to topstitch, heirloom stitch and pintuck.
Stretch and Ballpoint
Stretch and ballpoint needles have a slightly more rounded tip than the universal needle. Use the stretch needle when sewing elastic fabrics, such as Lycra or spandex and the ballpoint needle when sewing heavy or loose sweater knits. The rounded tip allows the needle to penetrate between the threads of the fabric rather than through them.
Metallic
Metallic needles are essential when sewing metallic fabrics. They have a large eye, thin shaft and sharp point to prevent the thread from breaking while trying to penetrate metallic fabrics. The metallic needle also has a large groove scarf to protect against skipped stitches and burrs on the thread.
Denim and Leather
Denim and leather needles sew these two heavy and difficult fabrics. Denim needles have a sharp point and deep scarf and are used with denim, canvas and upholstery fabrics. Leather needles have a point that resembles an arrowhead to pierce the leather without breaking it. You can also use this kind of needle on suede and vinyl.
Embroidery
Embroidery needles are used for machine embroidery or embellishment. They have a rounded but sharp point and a large eye to prevent decorative threads from breaking. Use embroidery needles with acrylic, rayon or other specialty threads.
Topstitching
Topstitching needles have a very sharp, thin point, a large eye and large groove to fit heavy thread or double strands of thread. You are meant to see topstitching, so the needle provides accurate, extra straight stitches.
Hemstitch and Wing
Hemstitch and wing needles allow you to perform openwork, drawn stitching on heirloom fabrics, linen and batiste. The needles have a flared shaft that creates decorative holes in fabrics with a tight weave.
Twin (Double)
Twin needles have two needles attached to a single shaft to sew two parallel rows of stitches. You can use twin needles for topstitching, hemming or pin tucking. Twin needles come in different varieties for the type of fabric you are sewing, such as denim, leather or metallic. They only attach to sewing machines that thread from front to back with zigzag capabilities.