Have a secret message to share or a surprise to reveal? Here's a fun science activity that can show you how it's done! How to make the Invisible Ink? First, add approximately 60ml of water and some baking soda into a bowl Next, mix everything together Then, dab the cotton swabs into the water and write your message! How to reveal the secret message? First, pour out some grape juice Next, dab a brush or a wet tissue and gently apply the grape juice all over the paper. Isn't