I love this one. Print and glue on a thin piece of cardboard. (Cereal boxes work great for this.) Punch holes where the x’s are, and put fishing line through the holes and tie on the back. Cut out the little black dots, and glue to the fishing line on the front. The fishing line sandwiches between the dots. Tie a ring or button to the back for easy sliding. You now have something similar to note finders available commercially, for a fraction of the cost.