Have you ever wanted to send a secret message to someone? Have you heard about invisible ink? Invisible ink is ink that cannot be seen until revealed with a secret trick. If you want to make your own, edible, and invisible ink, follow the directions below!
To make your invisible ink message, you will need the following:
- a few small containers
- at least one of the following:
lemon, orange or grapefruit juice
baking soda solution*
*(You can make the sugar and baking soda solution by mixing sugar or baking soda with a little bit of water until the water is saturated with the sugar or baking soda.)
- cotton swabs
- a piece of paper
- a heat source, such as a hair dryer, an electric iron, or an oven (set to a low heat, around 250 degrees, and check your message every few minutes!)
- a plastic tray
First, place your piece of white paper on the plastic tray. Then, dip a cotton swab into one of your invisible inks, write your secret message on your piece of paper, and wait for the message to dry. I used lemon juice, a sugar solution, and a baking soda solution for my invisible inks.
Once the message has dried, put it under your heat source (a hair dryer or iron) and watch your message reveal itself!
What is the science behind your invisible ink message?
Well, what do all of the inks have in common? Lemon juice, orange juice, grapefruit juice, milk, sugar, and baking soda are all edible (they are all things that you can eat). Now, think about when you bake cookies for too long. They turn brown or black. Thus, when we ”bake” our edible inks, they become brown or black also!
My lemon juice became a light yellow and my baking soda solution turned a light brown. My sugar solution didn’t show up very well, and I think it’s because I didn’t mix enough sugar into the water. If you use the baking soda or sugar solution, make sure you use enough baking soda or sugar!
Which “ink” did you use? Did you try multiple inks? Which did you prefer?