Steganography

"Steganography is the technique of concealing the fact that a message ever existed. The most common way to do this is by using secret inks or microdots." (Page 50, from Spy's Survival Handbook written by Laban Carrick Hill, Scholastic c.2003)

Over the years, I have repeatedly tried to find a way to use lemon juice writing with kids without using an open flame to expose the hidden message. I tried the naked light bulb method (according to some resources I looked up today you need at least a 100 watt bulb), and a bright flashlight; neither were successful. Success was found when I read the suggestion to use an iron. This photograph shows a message I created for my class last week, it was left behind as a clue. A couple of students were quick to pick up the idea that a blank piece of paper in the middle of the crime scene might not be blank at all but a secret message. There are several methods for producing secret ink messages. The preceding link lists several methods and I plan on trying out the lemon juice writing revealed by red cabbage liquid. This method would be a great segue into using red cabbage liquid as a acid/base indicator. But that's another blog posting for the future.

Each student produced their own secret message during class. I brought fresh lemons, cut them and squeezed the juice into plastic cups for the kids. Using a Q-tip, the kids wrote their messages, once dry we pressed them with the iron (use a folded towel to cover your table surface, I happen to own a pressing pad a by product of my quilting hobby-handy for taking to sewing classes) using the high setting. Eureka! The messages were revealed.