Buzz
Would you like to write down your password without anyone noticing, or perhaps send a secret message to someone? Once you learn how to write with invisible ink, you will soon feel like a secret agent.
Steps
Invisible Ink Made from Lemon Juice
Squeeze half a lemon into a bowl.
Add a few drops of water to the bowl. Stir thoroughly with a spoon.
Dip the cotton swab into the lemon juice solution and write your message on a piece of white paper. You can replace the cotton swab with a feather, toothpick, fountain pen, paintbrush, or calligraphy pen.
Wait for the invisible ink to dry. Once the ink dries, your message will disappear.
Hold the paper with the invisible message near a lightbulb or a flame/candle. Move the paper closer to the light or flame until the message reappears. Be careful not to place the paper too close if you're using fire or a candle.
Baking Soda Invisible Ink
Dip the cotton swab into a mixture of 1/4 cup (60 ml) baking soda and 1/4 cup (60 ml) water. Write your message on a piece of white paper using the cotton swab.
Wait for the ink to dry.
Dip a paintbrush into grape juice or any other dark fruit juice. Brush the juice onto the surface of the paper and wait for the message to appear.
Milk Invisible Ink
Pour milk into a shallow dish and dip the cotton swab into the milk.
Use the cotton swab to write a message on the white paper. Wait for the milk to dry.
Wait for the writing to dry for about 30 minutes.
Expose the paper with the message to a heat source. You can use a lightbulb, candle/flame, or an iron. The milk will heat up slower than the paper, causing the writing to appear.
Invisible Message Written with White Crayon
Use a white crayon to write a message on the white paper.
Use watercolor and a paintbrush to brush onto the surface of the paper. The message will appear.
Invisible Message Without Ink
This method relies on pressure and the indentations left on the paper.
Use two sheets of paper. Place one on top of the other.
Write the message on the top sheet. Use a pencil or pen and apply firm pressure while writing the message.
Remove the top sheet of paper.
Use a pencil and gently rub over the bottom sheet of paper. The message will appear, similar to chalk writing on a blackboard.
Tips
- If you don't have a white crayon, you can use a white candle to write the message and then apply watercolor as you would with crayon.
- For the lemon juice method, black paper works best.
- To reveal the message written with lemon juice or milk, you can also place the paper under a cloth and iron over it to bring out the writing. Alternatively, place the paper in an oven at 177°C for a few minutes until the message appears.
- In the white crayon method, you don't necessarily have to apply paint. Simply hold the paper slightly tilted near a window during the day. While it won't be fully visible, you can still read it, and it's much simpler.
- In the white crayon method, instead of coloring the paper, you can also use a thick-colored marker.
- Be sure not to add too much water to your mixture.
Warning
- Be cautious to avoid burns or fires when heating the paper.
What You Will Need
- Lemon juice
- Water
- Small bowl
- Spoon
- Cotton swab, toothpick, or paintbrush
- White paper
- Light bulb
- Baking soda
- Water
- Whisk
- Paintbrush
- Grape juice
- Milk
- White crayon
- Watercolor paints
- Brush
