1 tsp. gelatin (any flavor)
2 tsp. boiling water
Stir until gelatin dissolves and let cool for just a minute or so. While still warm, paint mixture onto the back of your "stickers" - use a paintbrush, a cotton swab, your fingers...whatever!
If you're doing a large sheet, it's easier to just coat the whole sheet and then cut apart afterward...
Let dry. Cut apart, if still needed. Lick, and then stick!