Method to make invisible ink: Writing top-secret messages for your "spy kids"

Here is a method to make invisible ink for writing top-secret messages for your “spy kids”.

1. Mix the baking soda and water in a small bowl. This is your invisible ink.

2. Dip a finger, cotton swab, or paintbrush into the “ink.”

3. Write your message on a piece of light-colored paper.

4. Let it dry completely.

Once dried the paper will be blank. Now to read the secret message

1. Lightly paint grape juice concentrate across the paper with a brush.

2. Your message will slowly appear as the juice saturates the paper.

Method to make invisible ink: Writing top-secret messages for your “spy kids”