If you ever thought about the endless possibilities of secret correspondence with friends, you will probably be interested in how to make invisible ink. At home, you can write a secret message in several ways. All of the methods presented below are absolutely safe and can be freely used in children's games about spies and scouts.
Simple recipe
Perhaps, in adventure books or children's detective stories you have already mentioned that ordinary lemon juice can be used as a secret substance for spy messages. Incredible, but true: in order to first-hand experience in how to make invisible ink, it is not at all necessary to own specific tools or technically sophisticated equipment. To conduct a fascinating experiment, you will need materials and items that can be found in any household, namely:
- half a lemon;
- water;
- a spoon;
- Bowl;
- cotton swab;
- White paper;
- lamp.
Lemon magic
Once you have collected all the necessary items, you can begin the first experiment. Subsequently, you will be able to proudly show your friends how to make invisible ink at home without any prior preparation. So:
- Squeeze a little lemon juice into a bowl and add a few drops of plain water.
- Mix juice and water using a spoon.
- Dip a cotton swab in the mixture and write your message on white paper.
- Wait for the juice to dry and become completely invisible.
- When you are ready to read or demonstrate your secret message, heat the paper by holding it closer to the light on.
How it works
Lemon juice is an organic substance that oxidizes and turns brown when heated. The juice is diluted with water, so that when the resulting mixture is applied to the paper, the letters and symbols practically disappear from the surface. No one will even guess that something is written on the leaflet until you heat up the message. Other substances work on the same principle - for example, orange juice, honey, milk, onion juice, vinegar and wine. If you are interested in how to make invisible ink at home in other ways, try chemical experiments or look at spy liquids under ultraviolet radiation.
Experiments with soda
A quick chemical experiment can be organized in just a few minutes, if you have at hand the usual baking soda. Moreover, science knows at least two ways of making invisible ink out of this inexpensive powder. Try the following:
- Mix baking soda with water in equal proportions.
- Using a cotton swab, toothpick, or brush to write, write a message on white paper, using a solution of baking soda as ink.
- Wait for the label to dry.
- The first way to read the secret message is to heat the paper - for example, under a light bulb, as is the case with lemon juice. The lines will turn brown.
- The second way is much more interesting. To implement it, paint over all the paper with black grape juice. The message will appear in the form of letters in contrasting colors.
Tips
If you already figured out how to make invisible ink, pay attention:
- If you prefer heating as a way of developing a message, make sure that the paper does not ignite - do not use halogen bulbs.
- Baking soda and grape juice interact with each other in an acid-base reaction, making changes in the color of words and letters.
- The solution can be made weaker by adding one part of baking soda to two parts of water. This will not affect the final effect.
- If you want to make the color change brighter and more obvious, take a grape concentrate instead of regular juice.
other methods
Those who are interested in how to make invisible ink will surely like the idea of using many different substances as the main material for secret correspondence. Indeed: many substances are suitable for espionage and reconnaissance correspondence, but secret agents need to remember with the help of which reagents each of them appears. If you have forgotten the perfect reagent, do not despair: most of the substances listed below can be expressed with acid. So, just paint the secret paper with lemon juice. Some messages appear when heated, so if you already know how to make invisible ink and write a magic letter with their help, keep a heat source with you.
For an experiment with secret correspondence are ideally suited:
- phenolphthalein (manifested by soda);
- vinegar or diluted acetic acid (you can see the message by dipping it in a decoction of red cabbage);
- table salt (silver nitrate is sufficient for developing);
- copper sulfate (you will need sodium iodide or ammonium hydroxide) ;
- iron sulfate (manifested by soda);
- corn or potato starch (iodine solution is needed for reading).
Now you know a lot about how to make invisible ink - you can go on reconnaissance!