This is my absolute favorite for finishing knit garment hems. You iron it in and it stabilizes your sewing, but remains stretchy. Honestly, it's a miracle!

HeatnBond Soft Stretch is a NO SEW, lightweight iron-on web adhesive specially designed to move with your stretch fabric while maintaining a strong bond! There is no added bulk and maintains a soft hand after fusing. Great to use with knits, stretch denim, spandex, jersey fabrics, fleece and flannel. 5/8 inch x 10 yards tape (15.9 mm x 9.1 m). Double-sided iron-on permanent adhesive. Designed for stretch fabrics. No sewing needed (can be sewn through if needed). Proudly made in the USA.