Size:170Silk thread is very smooth so travels through even the lightest most delicate fabrics without leaving a mark as well as being very strong (especially when used in conjunction with beeswax) it is a superb choice for a large variety of hand sewing projects. Other uses include decorative stitching. Silk is very strong and quite durable; you can even use it in fishing. While it isn't as cheap as a cotton embroidery fLose it isn't outrageously priced. It's about the same as an overdyed fLose or metallic. There are times when using silk thread is absolutely worth it. Just as quilters know to use the best quality fabrics for a lasting quilt better quality threads will raise the bar on your needlework.