It's Sew Emma 3/4" Cross Stitch Finishing Tape from Lori Holt: 3/4" x 30 Feet Acid Free For Needlework Mounting and Finishing, Crafting

This acid-free tape measures 3/4" x 30 feet/10 yards and features double-sided adhesive for securing fabric, needlework, and other art pieces. Made in the USA.