ru en
Show your kid how to write a letter with invisible ink!

Show your kid how to write a letter with invisible ink!

5 to 8 years

Want to write a letter and keep it secret? Are you wondering how to go about it? Are you aware of the option of writing a letter with invisible ink? Invisible inks are the best way to keep your message a secret. The writing disappears soon after you have written it, making it meaningless to people. The message can only be read by the person who knows how to reveal it. While spies and detectives have been using invisible inks for a long time, it can be used to convey personal messages as well. In the following lines, we provide three recipes for making invisible ink.    



Recipes For Making Invisible Ink 



Materials Required


  • Heat Source, in the form of Light Bulb
  • Lemon Juice/ Baking Soda/ Cornstarch and Iodine
  • Small Bowl
  • Cotton Swab
  • Plain White Paper
  • Paint Brush

Using Lemon Juice 


  • Extract the juice of a lemon in a small bowl or container.
  • Dip a paint brush into the bowl containing lemon juice and use it as a pen.
  • Write your message on a plain piece of paper.
  • Once the message has been written, keep the paper aside for sometime, so that it dries well.
  • When the paper gets dried, hold it near a light bulb or any other source of heat, so that the paper gets heated.
  • Now, read the message. The words will appear in a pale tan or brown color.

Using Baking Soda 


  • Take equal quantities of baking soda and water and mix them in a small bowl.
  • Dip a paint brush into this mixture and use it as a pen.
  • Write a message on a plain piece of paper.
  • Once you have written the message, let the paper dry.
  • Now, place the paper in front of a light bulb or any other source of heat so that it gets heated.
  • All you need to do now is read the message. The words would emerge in brown color.

Using Corn Starch 


  • Mix 2 tbsp of cornstarch and 1 tbsp of water. Now, heat the mixture until the cornstarch gets properly dissolved.
  • Dip a paint brush into this mixture and write a message on a plain piece of paper.
  • Allow the paper to get dry completely.
  • In the meantime, prepare an iodine solution. Mix iodine and water in the ratio of 1:10.
  • Once the paper, on which the message has been written, gets completely dry, paint it with the iodine solution, using a brush or cotton ball.
  • The message will emerge in purple letters.

If you enjoyed this activity, you may also like the following activity, too

By signing up or otherwise using this website, you accept and agree to Terms of Service and Privacy Policy

Content is available for users with Gold status

You can purchase it in mobile applications for iPhone and Android

Paywall illustration