How to make invisible UV ink. Invisible ink

How to do invisible ink? There are a number of ways to do this. With the most popular available options Let's take a look at the presented material.

What is invisible ink

Invisible, or sympathetic, ink is a specific solution that is used to secretly display information on plain paper. In order for the inscriptions to appear, the use of a catalyst is required, be it chemical substances, warmth, light, etc.

This method of transmitting secret data was widely popular back in the last century. As a rule, a secret message was written on ordinary white paper with sympathetic ink. Then a regular one was applied on top of a regular pen, visible text arbitrary content. Such letters were usually heated, the secret code was studied, and then the paper was sent to the fire.

Today it is possible to make invisible ink using ultraviolet light, or rather - fluorescent paints, which are used to create watermarks. Such substances make it possible to carry out high quality printing on banknotes, documents, strict reporting forms. IN normal conditions fluorescent dyes remain invisible. They appear only under the influence of ultraviolet radiation.

There are a whole host of options for preparing fairly effective solutions for creating secret inscriptions. We'll look at common ways to make invisible ink below.

Invisible ink made from lemon juice

How to make invisible ink at home from regular lemon juice? To do this, you need to squeeze the liquid from half the fruit into a container, add a few drops of water and mix the resulting composition thoroughly. Then you should soak a cotton swab in the solution and write a message on paper with it. Finally, all that remains is to dry the secret letter.

Lemon juice is essentially a fairly concentrated acid. Substances of this nature change color to a darker color when exposed to high temperature. In order for the text written with lemon juice to appear, you need to lightly iron the paper with an iron or hold it over a candle.

How to make invisible ink from copper sulfate

Copper sulfate dissolved in water gives a substance of a pale blue, barely noticeable hue. Therefore, the presented substance is excellent for creating invisible messages.

How to make invisible ink using copper sulfate? To do this, it is necessary to dissolve a small amount of powdery substance in ordinary water. Next, using the same cotton swab or match, you can begin to apply the message to paper.

How to reveal information from a secret letter? In order for what is written to become visible to the eye, it is necessary to hold the paper for some time over a container filled with ammonia. The latter's couples will enter into chemical reaction with copper sulfate. The result will be the appearance of distinct letters in a bright blue hue on the paper.

How to make ink from rice water

Rice water contains a significant concentration of starch, which, after drying on paper, does not leave clearly visible marks. To develop a message written with liquid from rice water, it is enough to moisten the paper with a non-concentrated iodine solution. The result will be the appearance of distinct blue text.

Invisible ink made from baking soda

How to make invisible ink from baking soda? The presented substance must be diluted in water to obtain a sufficiently saturated solution. Next, you can start creating your message. To write inscriptions on paper, you can use any convenient object at hand.

Before you start developing your letter, you need to let the invisible ink dry thoroughly. In order for secret inscriptions to be visible, the paper must be exposed to heat. Here you can use a hot iron, hold the sheet over gas stove or a candle. After about a minute, previously invisible inscriptions will begin to appear and will have a brownish tint.

Invisible ink made from milk

This method is one of the simplest and most accessible. To create secret messages, you just need to dip a cotton swab in milk and write on paper. Next, just let the sheet dry and smooth it on a hard surface.

To reveal the information, you need to hold the letter under an electric light bulb. Since milk is heated much slower compared to paper, this will allow the hidden message to emerge.

Finally

So we found out what available methods exist for making invisible ink at home. Use any of the above solutions to play with own child become spies or exchange secret letters with friends.

Question-answer No. 20
Added: 12/05/2013

Since time immemorial, almost immediately after the advent of writing, people began to think about the possibilities of maintaining the secrecy of correspondence. Of course the best way Invisible ink has become a solution to such problems. Secret writing, applied to paper using special substances, made it possible to hide a lot of different secrets. A meaningless note, visible to others and written over the disappeared words, carefully kept its secret until a “craftsman” appeared who was able to read the text hidden between the lines.

Today, invisible ink, also called sympathetic ink, can be made independently at home. This unique invention can be used for various purposes, but in most cases, it is the basis for all kinds of comic pranks. For maximum masking of records, do not visible ink To hide the slightest hint of their presence, you can write something else over such colorless text, for example, a poem by Pushkin.

There are several recipes for making sympathetic ink:

First way

In earlier times, liquids were used as disappearing ink, which after drying did not leave the slightest trace on paper: white wine, beer, milk. To develop a recording made from the above “ink”, you will need ordinary ashes. To enhance the effect, before treating with ash, the paper can be slightly moistened with breath.

Second way

Very good results can be achieved using rutabaga juice, Apple juice, onion juice, citric acid. To manifest messages written in such invisible ink, it is enough to hold a sheet of paper at a distance of ten centimeters from the fire. If you don’t want to come into contact with fire, you can simply hold the paper under a hot iron.

Third way

Starch can also be used to make invisible ink. To read the inscription, the paper should be treated with a weak iodine solution. As you know, under the influence of iodine starch turns blue.

Fourth method

Ordinary washing powder can also be a good basis for creating colorless ink. To read the inscription, just place it under a source of ultraviolet radiation. As a rule, such lamps are used in nightclubs, solariums, and devices designed to detect counterfeit banknotes.

Fifth method

Often, in extreme conditions, ordinary saliva played the role of ink. A weak ink solution was used for development.

Sixth method

If you use a syringe to inject a small amount of the colorless indicator phenolphthalein into a quill pen, you will get a good makeshift pen. To develop the recording she made, you need to use a swab soaked in any alkali (sodium hydroxide or potassium hydroxide). The letters will instantly take on a crimson color.

Seventh method

You can write colorless messages with rice water. To develop a recording, it is enough to treat it with a weak alcohol solution of iodine. As a result, the letters turn blue due to the starch contained in the rice.

Eighth method

You can make notes on paper using a highly concentrated solution of cobalt chloride. This text appears beautiful blue when heated. Moreover, such a record can subsequently be “made” to disappear again. To do this, just breathe on it or hold it over the steam.

Ninth method

Dextrin and iodine will also help create disappearing ink. Dextrin is a substance obtained by heating starch. Add 3 grams of dextrin to 30 ml of iodine and pass through filter paper. Use the resulting blue ink to write some text. After a couple of days, the recording will disappear without a trace, and it will be impossible to restore it, thanks to the volatility of iodine.

Since ancient times, humanity has tried to invent invisible or, as they are also called, sympathetic ink, which is not visible to the eye under normal conditions, but begins to appear after exposure to any chemical elements, heating, ultraviolet rays. They were used to send secret messages, store important information, secret correspondence.

In ancient times, these were publicly available substances that could be found in every home. For example, secret writing using milk, lemon juice, rice water, wax, apple and onion juice, and rutabaga juice was very successful. Later, options appeared for making sympathetic ink using aspirin tablets, copper sulfate, iodine, and washing powder.

Modern UV ink

Science does not stand still, so in our time you will no longer surprise anyone with invisible ink produced industrially. Compositions that glow under ultraviolet lamps. There are even pens with ultraviolet ink available for sale, which can be found in spy stores.

An alternative to such a pen can be invisible anti-counterfeiting paints and pigments. They are powdery substances that can be used to mark banknotes, securities, and clothing. In daylight, the powder is completely indistinguishable, but in ultraviolet light every grain or powder becomes visible.

How to make invisible fluorescent ink at home

As a good fluorescent ink, you can use regular laundry detergent containing optical brighteners. After diluting the powder with a small amount of water, you can begin to write a secret message. The dried solution will not leave imprints on the paper, but will be perfectly visible in the light of an ultraviolet lamp.

Can also be purchased separately. As a rule, they are used to impart whiteness with a bluish tint to clothing, fabrics, and paper intended for printing. The powder can also be used to create sympathetic ink. This ink appears on all types of paper.

Another way to make invisible ink is to use aspirin tablets and alcohol. 2-3 aspirin tablets should be dissolved in a small amount of alcohol. If any sediment remains during dissolution, the liquid should be filtered. After this, you can begin secret writing. Such ink does not glow on all types of paper; this method is not applicable if you write on printer paper.

You can also use the following drugs to prepare ink, which you can try to purchase at the pharmacy:

• curcumin;
• quinine sulfate;
• trypoflamin.

Sodium fluorescein can also be used, but its native color may stand out on white paper after application, so this ink is not invisible.

Sympathetic ink is a solution for writing information on paper. They differ from ordinary ink in that the message written with them cannot be seen until certain conditions are applied, be it heat, light, etc. This method of transmitting information has been one of the main elements of encryption at all times. As a rule, on clean slate secret information was first written on paper, sympathetic ink was used. After drying, a regular message was applied on top of the transparent inscription using simple visible ink. Such letters, as a rule, were heated to create a secret code, and then the sheet was destroyed. There are many different recipes for invisible ink, including purely chemical ones, which are sold in finished form today in departments stationery. However, you can prepare such spy ink yourself.
To do this you will need: Regular baking soda, a little warm water, spoon, toothpick with cotton wool (you can also use a cotton swab or refillable fountain pen), a sheet of paper and a candle.

Step 1. Baking soda must be diluted in water to form a concentrated solution. Allow the mixture to cool slightly. It is not necessary to ensure complete dissolution of the soda.

Step 2. If there is a fountain pen, which can be filled with freshly prepared solution.

Then we use it. If you don’t have such a device at hand, you can use a cotton swab or a regular toothpick with a piece of cotton wool at the end.

It is necessary to dip it in an aqueous solution of soda and squeeze it lightly. After this, you can safely write a message on a blank sheet of paper.

Step 3. It is advisable to let the ink dry a little before starting to develop the letter. In order for the secret record to become visible, the sheet with it must be held over heat. This could be an iron, gas or electric stove, but in our case a regular candle was used. To prevent the paper from catching fire, you need to move it lightly over the flame.

Step 4. If everything is done correctly, then after about 30-40 seconds a yellow-brownish inscription will appear. Ready! The inscription is revealed. You can also heat a sheet with a secret recording on a battery, but this will take much longer, and the recording itself will not be as bright.

You can also use lemon juice or concentrated vinegar instead of soda solution, however, these substances leave slightly visible marks on the paper, which no longer corresponds to the “secret” stamp.

Project for primary school. Spy (cute) ink

Brief summary of the research work
Learning the secrets of secret writing is a fascinating process. In this work, the author describes what invisible ink is, the history of its origin; An attempt was made to prepare several types of sympathetic ink at home and use them to write invisible text. The hypothesis put forward that if “spy” ink is made in secret laboratories developing special equipment for spies, then some of them can be made at home, was completely confirmed during the experiments.
This work will be of interest to anyone who loves various mysteries.
Table of contents
Introduction 3
Chapter 1. Theoretical study of problem 4
1.1. What is invisible ink 4
1.2. The history of invisible ink 4
1.3. Types of sympathetic ink: 5
1.4. Technology for making invisible ink at home 6
Chapter 2. Practical study of problem 7
2.1. Questioning classmates on research topic 7
2.2. Tools and accessories for writing 7
2.3. Testing invisible ink 8
Conclusion 9
List of information sources 10
Appendix 11

List of information sources
1. References
1.1. Aleksinsky V.N. Entertaining experiments in chemistry. – M.: Education, 1995 – 96 p.
1.2. Lavrova S.A. Riddles and secrets of ordinary things. – M.: White City, 2006 – 48 p.
1.3. Lavrova S.A. My first book. Entertaining chemistry for kids. – M.: White City, 2009 – 128 p.
1.4. What? For what? Why? Big book of questions and answers / Trans. K. Mishina, A. Zykova. – M.: Eksmo, 2007 – 512 p.
2. Other sources of information
2.1. Invisible ink. Disappearing ink. [Electronic resource].
2.2. Do it yourself, with your own hands. Invisible ink. [Electronic resource].
2.3. Sympathetic (invisible) ink. [Electronic resource].
2.4. How to make invisible ink? [Electronic resource].
2.5. Who invented ink? [Electronic resource].
2.6. What is sympathetic ink used for? [Electronic resource].
2.7. Children's lessons. How to make invisible ink. [Electronic resource].

Application
Annex 1
Classmate survey results
Have you watched movies about spies?
Do you know about invisible ink?
What can you make invisible ink from?
Would you like to learn how to make invisible and disappearing ink?
What can you use to make invisible ink?
Appendix 2
Homemade Sympathetic Ink Recipes
Invisible ink from lemon - squeeze the juice of half a lemon and dilute it with the same amount of water, develop with heat;
Invisible ink from onions - prepare onion juice and use it as ink, exhibit heat;
Invisible ink from milk - take milk and use it as ink, dry it, develop it over a candle or lamp;
Invisible ink from soda - prepare a concentrated solution of soda - 1 teaspoon per 10 ml. – 2 – 3 teaspoons of water, move everything, use as long-lasting ink, develop with heat.
Invisible ink from starch - prepare a solution of starch with water, move everything and cook until a homogeneous mass is formed, use it as ink that lasts a long time, develop it with an iodine solution (1:10).
Appendix 3
Experiment 1: Making invisible ink from lemon
For this we will need: half a lemon, a glass, a brush, White list paper. Squeeze the juice from the lemon into a glass and add the same amount of water. Dip the brush into a solution of lemon juice and water and write something on paper. After the inscription is made, it must be allowed to dry. To develop the inscription, you need to heat a piece of paper, for example, iron it with a hot iron. Lemon acid darkens when exposed to temperature and thus my ink becomes visible.
Experiment 2: Making invisible ink from onions
For the experiment we will need the same thing as for the previous one.
Take half an onion, grate it on a fine grater and squeeze the juice through a piece of gauze into a glass. Apply the onion juice with a brush to the paper and wait for it to dry. When dry, the onion juice is slightly noticeable on the paper, and has a not very pleasant smell, which makes this ink imperfect. We will develop it in the same way - by heating. The onion juice darkens when exposed to heat and the ink becomes visible and turns brown.
Experiment 3: Making invisible ink from milk
Pour milk into a glass. Dip the brush in milk and write on a piece of white paper. Let the milk dry. There will be no trace or smell left of the letters. We will develop it in the same way - by heating, since milk will change color when heated. The milk actually changed color.
Experiment 4: Making invisible ink from baking soda
It is necessary to prepare a saturated solution of ordinary baking soda in water. Dip the brush into the baking soda solution and write on a piece of white paper. Immediately behind the brush, the water evaporates, and there seems to be nothing on the sheet of paper. A secret letter is also revealed very simply: by exposure to heat. When heated with an iron, dark brown text appears. Moreover, this text turned out to be the brightest and most homogeneous of all the previous ones.
Experiment 5: Making invisible ink from starch
Starch can also be used to make invisible ink. It is necessary to prepare a saturated solution of starch in water. I used a brush, as in previous recipes. To read the inscription, the paper should be treated with a weak iodine solution. As you know, under the influence of iodine starch turns blue.