Invisible Ink & Mirror Images


Invisible Ink

Invisible ink has been used to conceal secret messages for a long time. You might remember the spy that used keys to hide invisible ink chemicals? Well the science of creating invisible messages has come a long way in the last 100 years. Professional scientists have developed invisible inks that are difficult to detect, even by the professional spy. If you'd like to experiment with invisible ink you can use some simple materials from home:

Invisible Ink Ingredients - Developed by Brady Schaures

1/4 cup white grapefruit juice
1/3 tsp. lemon juice
Pinch of sugar

Directions


Use a Q-tip to dip into the invisible ink and write you message on white paper. After the message dries you can use a hot iron, burning match, or lighter to burn the ink on the paper. CAUTION - Don't try this at home unless you have direct adult supervision. It is recommended that you use an iron to avoid the chance of fire.

The paper will turn brown and eventually burn up if you overheat the paper. The secret is to heat up the paper a little, see if the message has appeared, and then try again until you can see the message on the paper.

You may want to experiment with other liquids around the house until you can create an invisible ink that can't be seen on paper until it is burned. Other juices are a great way to write invisible ink on colored paper as well. Try orange juice, cranberry juice, and others.

Mirror Images


By making use of a computer you can easily create images that are backwards, only readable when seen in a mirror. Simply write your message and use painting or drawing tools to flip the message horizontally. Then print your message and hold it up to a mirror. The message below has been flipped horizontally and can be read in a mirror.



What is the message above?
Flip the text horizontally once you're ready to make it a mirror image.

Camouflage Crayons


Another way to hide a message is to use crayons. Use a pencil to write a message as lightly as possible on some paper. Then use crayons to cover up the message. If possible, draw a picture that is unsuspecting and looks normal. To see the secret message use a sharp knife or razor blade to scrape off the crayon marks. Be careful when handling the knife!

*Histiaeus, in 500 B.C., wrote a secret message on a slave's head, waited for his hair to grow back, and sent his slave cross enemy lines. When his head was shaved the message appeared!