we found that many unfinished bottles of water are thrown away after group activity, mostly because it's easy to forget which bottle belongs to whom people do have the intention to save water. in fact, they are trying different ways to tell the bottles of party. yet it seems not working very well. how can we recognize our bottles easily on the bottle label? we've painted layer of coding that can be easily marked by scratching. people can just use their finger to make their bottle, introducing signature a bottle. with a small change to the bottle label, identifying water bottle can be easy and fun. most of all, it save water. now, mark your bottle and dreams of the last drop model finger nature will. thank you.