How to Make Invisible Ink Pens
Every child loves secrets and codes, and nothing is more secretive than invisible ink. Fortunately, there is nothing secret or mysterious about making invisible ink. With a little bit of cornstarch and water, you can write secret coded messages that can only be deciphered by someone with the proper know-how. You can write them with your finger or a paint brush if you want, or take the extra step and make a fully functional invisible ink pen.
Things You'll Need
- Felt-tipped pen
- Knife
- Scissors
- Marker
- Gloves
- Paper
- Starch
- Water
- Bowl
- Sponge
- Lightbulb
- Grape juice
Instructions
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1
Open up a felt-tipped pen or marker and remove the ink capsule from inside. If your felt tipped pen doesn't open easily, you can use a knife to pry it apart.
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2
Soak the pen in water to remove any ink left-over from the tip and the body. Do this several times until the water is clear.
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3
Cut a piece of sponge the size of your pen capsule. It doesn't have to be exact, but it should be able to fit inside.
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4
Make a mixture of half baking soda and half water and dip the sponge in it. This will be your invisible ink.
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5
Put the sponge inside the pen and close the pen up. Write your invisible message on a piece of paper.
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6
Hold the message near a light bulb or other heat source to decipher it. It will become yellow or brownish. You can also cover the page with grape juice. The message will stand out as a pale color.
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Tips & Warnings
Use an old, used-up pen and wear gloves if you don't want to get ink all over your hands. If there is still water left in the pen tip, you may have to write for a bit before the invisible ink comes out.
