Invisible Ink

I was just watching the build up to the All Blacks playing against Argentina and a lady was interviewing a guy from weka workshop and mentioned a map with invisible ink.
It got me thinking about whether there was in fact invisible ink, so I decided to research it over the internet.



It turns out there is at least four ways of making invisible ink.

1. Making it with lemon juice
• Squeeze the juice of half of a lemon into a bowl.
• Add a few drops of water. Stir the juice and water with a spoon.
• Dip a cotton swab into the lemon juice mixture and write a message on a piece of white paper. A feather, a toothpick, a fountain pen, a paintbrush or a calligraphy pen will also work in place of the cotton swab.
• Allow the invisible ink to dry. As the ink dries, your message will disappear.
• Hold the paper that contains your invisible ink message over a light bulb. Keep the paper near the bulb until the message reappears.
2. Making it with baking soda
1. Mix 1/4 cup (60 ml) of baking soda with 1/4 cup (60 ml) of water in a small bowl using a whisk or a spoon.
2. Dip a cotton swab into the baking soda and water mixture. Use the swab to write a message on a white piece of paper.
3. Wait until the ink is dry.
4. Dip a paintbrush into some grape juice concentrate. Paint the grape juice over your message and wait for the message to appear.
    
3. Making it with milk
1. Dip a cotton swab into a shallow dish of milk.
2. Use the cotton swab to write a message onto a white piece of paper. Allow the milk to dry.
3. Place the paper over a light bulb. The milk will heat up at a slower rate than the paper, which will cause the message to reappear.
    
4. Or using a white carayon
• Use a white crayon to write a message onto a white piece of paper.
• Paint over the message using watercolors and a brush. The message will reappear.

Not as magical as I had thought, in my imagination when I heard the words "Invisible Ink" but it is something fun I could do with my girls on a rainy day, which we are getting a lot of lately.