Invisible Ink (Grades 3-5)

Write a mysterious message using simple household ingredients!

Check out this video on How to Make disappearing ink out of vinegar.

Making invisible ink is a lot of fun! You can pretend you are a secret agent, or draw a secret map that leads to your hidden treasure. All you need is some basic household objects, and a little help from a grown-up.

What You Need

  • Vinegar or lemon juice
  • Water
  • Spoon
  • Bowl
  • Cotton bud
  • White paper
  • Lamp or other light bulb

What To Do

  1. Pour vinegar or lemon juice into a bowl, and add a few drops of water. Mix with a spoon.
  2. Dip the cotton bud into the mixture and write a message onto the white paper.
  3. Wait for the juice to dry so it becomes completely invisible.
  4. Ask an adult for help or permission with this step: When you are ready to read your secret message or show it to someone else, heat the paper by holding it close to a light bulb.  

What’s Happening Here? 

Lemon juice oxidizes and turns brown when heated. Diluting the lemon juice in water makes it very hard to notice when you apply it the paper. No one will be aware of its presence until it is heated and the secret message is revealed. Other substances which work in the same way include orange juice, honey, milk, onion juice, and vinegar.