Wooly nylon thread is unique when compared to other types of thread because it is stretchy. Whereas most cotton and polyester threads create stable seams, wooly nylon creates seams that recover after being stretched, which is a huge plus when sewing knit fabrics. Due to its stretchy nature, this thread typically is intended to be used with stretchy fabrics. As the name suggests, it is made from spun nylon fiber that results in a thread that is durable, soft, and strong. Stretchy nylon thread such as this is usually sold on small cones and intended to be used on a serger.
The increased coverage that is offered by this thread makes it ideal for use on rolled hems, in addition to regular serged seams. Rolled hems sewn with it are an easy alternative to traditional hems, especially on specialty fabrics, such as dancewear knits and swimwear fabric. In this case, the nylon offers comfortable seams that are soft and don't scratch tender skin. This thread is especially well-suited for projects such as lingerie, swim suits, and baby clothing, and a wide range of fabrics can be sewn with it.
When compared to traditional thread, the color selection for wooly nylon thread can be limited. Even so, seamstresses often find a sufficient number of choices to make a reasonable match. Aside from thread color, there is a range of thread types available including metallic, variegated, and extra plush. In addition to creating seams, wooly nylon is also perfect for adding a decorative touch to tablecloths, napkins, and other home decor projects. Some tension adjustments may be necessary due to the texture differences between this type and regular thread.
Wooly nylon typically is intended for use on a serger, which is a sewing machine that creates overlock seams while at the same time cutting away the excess seam allowance. A typical serger uses four spools of thread; two are used for the needles and the other two are used for the loopers, which are the mechanisms that create the overlock stitch. Wooly nylon thread should be used in the loopers of a serger, while regular polyester synthetic thread should be used in the needles. Nylon thread with stretch can also be used in the bobbin of a regular sewing machine to add stretch to a traditional seam. Sewing professionals generally do not recommend using it in the needles, as sewing machines generally have trouble feeding the fuzzy thread through their tension mechanisms.