From the manufacturer:
This 100 yard satin string is ideal for dressing up wrapped gifts as well as gift bags for any occasion. It is the perfect embellishment for handmade greeting cards, scrapbook pages and jewelry making projects. Available in a variety of colors. It can also be used as a more elegant substitution for baker’s twine on confectionery products. This product measures 3mm in width. Satin string is also known as rattail or rat tail cord. Rattail cord is used for creating simple lining on garments and fashion accessories.