The idea we propose today is ideal for a fun afternoon with the children. What they always wanted: write invisible messages and secrets that only the recipient can reveal. It will surprise them.
The invisibility is not a science fiction myth. Human beings have always been attracted to being invisible and incorporeal in order to infiltrate without being seen in all those places where their presence is uncomfortable. It is the innate morbid curiosity. This desire to know what is forbidden to us has led to espionage practices, which are nothing more than a kind of "corporeal invisibility". Bodies that exist physically, but with hidden, invisible identities.
With the invisible ink We won't give away state secrets, but children can have a very fun and stimulating time. Let's get to it. Remember: this is Top Secret.
You will need:
- One lemon.
- A bowl.
- A paintbrush.
The secret ink is none other than lemon juice. For writeSqueeze the lemon into a bowl. Dip the paintbrush into the liquid and we write the text on the paper. Try to use a fine-tipped brush with tightly closed bristles for better writing. You can also use an ear bud as a tool.
Where's the fun in that? In the next step: if we pass an iron (or other heat source, such as a light bulb) over the paper, the secret message will be revealed.
The crux of the matter is that the ignition temperature of the lemon is lower than that of the paper, which is why the letters appear without the paper burning (as long as we don't overdo it, of course).
More inks: yes we write with milk, when we heat it up the line will be brown.
The last tip: don't reveal this confidential information to too many people 😉.