How to make invisible ink at home?
How to make invisible ink at home?

If you've ever wondered about the endless possibilities of secretly texting friends, you're probably wondering how to make invisible ink. There are several ways to write a secret message at home. All the methods below are absolutely safe and can be used freely in children's spy and intelligence games.

how to make invisible ink at home

Easiest recipe

Perhaps in adventure books or children's detective stories you have already met the mention that ordinary lemon juice can be used as a secret substance for spy messages. Incredible, but true: in order to figure out from your own experience how to make invisible ink, it is not at all necessary to own specific tools or technically complex equipment. To conduct a fascinating experiment, you will need materials and items that can be found in any household, namely:

  • half a lemon;
  • water;
  • spoon;
  • bowl;
  • cotton swab;
  • white paper;
  • lamp.

Lemon Magic

how to make invisible ink

Once you have collected all the necessary items, you can proceed to the first experiment. Subsequently, you can proudly demonstrate to your friends how to make invisible ink at home without any prior training. So:

  • Squeeze some lemon juice into a bowl and add a few drops of plain water.
  • Mix juice and water using a spoon.
  • Dip a Q-tip in the mixture and write your message on white paper.
  • Wait for the juice to dry and become completely invisible.
  • When you're ready to read or share your secret message, heat the paper by holding it close to the light bulb.

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 paper, the letters and symbols practically disappear from the surface. No one will even guess that something is written on the leaf 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 wondering how to make invisible ink at home in other ways, try doing some chemistry experiments or looking at spy liquids under UV light.

Experiments with soda

how to make invisibleinky

A quick chemistry experiment can be set up in just a few minutes if you have regular baking soda on hand. What's more, science knows at least two ways to make invisible ink from this inexpensive powder. Try this:

  • Mix equal proportions of baking soda and water.
  • Using a Q-tip, toothpick or paint brush, write a message on white paper using the baking soda solution as ink.
  • Wait for the lettering 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 stitching will turn brown.
  • The second way is much more interesting. To bring it to life, paint over all the paper with black grape juice. The message will appear as letters in a contrasting color.


If you have already figured out how to make invisible ink, please note:

  • If you prefer heat as a way to develop your message, make sure the paper doesn't ignite - don't use halogen bulbs.
  • Baking soda and grape juice interact with each other in an acid-base reaction, producing changes in the color of words and letters.
  • The solution can be made weaker by adding one part baking soda to two parts water. This will not affect the final effect.
  • If you want to make the color change more vivid and obvious, use grape concentrate instead of regular juice.

Other ways

how to make invisible ink at home

Those who are interested in how to make invisible ink will surely love the idea of ​​using many different substances as the main material for secret correspondence. Indeed, many substances are suitable for espionage and intelligence correspondence, but secret agents need to remember which reagents each of them manifests with. If you forget the perfect reagent, don't despair, most of the substances listed below can be developed 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 it, keep a source of heat with you.

Perfect for experimenting with secret correspondence:

  • phenolphthalein (development with soda);
  • vinegar or dilute acetic acid (you can see the message by dipping it in red cabbage broth);
  • table s alt (silver nitrate is sufficient for developing);
  • copper sulfate (need sodium iodide or ammonium hydroxide);
  • iron sulfate (manifested by soda);
  • corn or potato starch (requires iodine solution to read).

Now you know a lot about how to make invisible ink - you can go explore!

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