Are you referring to the white binding? You can make this from cutting strips of knit fabric. If you want to see an example of me sewing on binding on a neckline, check out our tutorial the Baby Onesie. Obviously, the size of my binding might be different than yours but the concept could still work. (http://youtu.be/6eVAQl0ROTM?t=3m3s) I hope this helps. If you finish your tank top, please post a pic 🙂