With these easy steps, you and your child can write a message on a piece of paper that is invisible until held up to a heat source like a hairdryer.
You will need a piece of paper, lemon juice, a thin tip paint brush, and a small bottle (a clean empty vanilla extract bottle or olive oil bottle will work).
Create a little bowl of lemon juice that your child can dip the brush in and use like paint.
Your child can write words on the paper, which will get damp from the lemon juice.
Once the page is dry, the “ink” will have disappeared. Now it’s ready to roll up and put it in the bottle.
When your child is ready to take out the message, unroll it and blow hot air on it with a hairdryer. The heat from the hairdryer will make the invisible ink appear magically on the page.
You can take turns writing each other secret messages and deciphering them!
We learned about this project from Mini Eco.