Lip Prints

Women who wear lipstick often leave lip prints on drinking glasses. At a scene, this kind of print would be collected as evidence during an investigation. Try the following activity to learn how lip prints can be used to solve crimes.

Materials
- Lipstick (dark colors work best)
- White paper
- Pen or pencil

Procedure
1. Put lipstick on both of your lips. Rub your lips together to spread the lipstick evenly.
2. Fold the white paper in half.
3. Place the folded piece of paper between your lips and firmly press your lips against it. Be careful not to slide your lips on the paper or else the lip print will smudge.
4. Remove the paper and unfold it. Write your name on the paper to identify the lip print as yours.
5. Examine your lip print. What do you notice about it? Are there any unique qualities that would let you identify it as yours?

More Fun Stuff to Do
Collect lip prints from several helpers. Make sure that you write each person’s name next to his or her print. Then leave the room and have one of your helpers make a lip print on a drinking glass. Can you identify who made the print?

Explanation
There are many ways to identify a person. One of them is cheiloscopy, or the study of lip prints. (The term cheiloscopy comes from Greek word cheilos, meaning “lip”.) Lip prints are unique and do not change during a person’s life. Although they are less commonly encountered than fingerprints at the scene of crime, lip prints found on drinking glasses, cups, and even letters can be valuable evidence. One problem with lip prints is that their credibility has not yet been established in courts of law.