It's been a labour of love getting the nail file stick just right. Sticky enough so it stays stuck to the Thumble whilst filing but not too sticky that you can't replace the nail file when needed. If you find that the nail has lost it stick please look at your technique. When removing the backing from the adhesive part of the nail file make sure you do not touch the adhesive. The natural oils found in your skin can affect it’s stickiness. Also make sure that the nail file has made good contact with the Thumble. Follow the contour of the Thumble and make sure it doesn’t catch the raised lip above the 3 small holes.