Floss is perfect for sewing: cheap and tearproof. Also you can fit a needle in the container (which has also a little blade to cut the thread) for a perfect sewing kit
50PCs Threads Stitch Thread Knitting Handmade Floss For Sewing Skeins Craft Embroidery Thread linha de costura Kit - AliExpress
How Many Strands Should I Use? – NeedlenThread.com
Amazon.com: Embroidery Floss, Cross Stitch Thread for Sewing and Hand Craft Embroidery | Suitable for Bracelet Thread Making | Set of 447 Skeins Rainbow Color Cotton Strings : Arts, Crafts & Sewing