How to Make Invisible Ink at Home

If you grew up watching Mission Impossible, Get Smart, and The Man from U.N.C.L.E. then chances are that you’ve always wondered what went into making invisible ink. The messages written in this secret ink could later be deciphered using a heat source to make the ink appear. While this is a great trick for TV and movies, we have to wonder if it really works. Below Nate from the YouTube channel, The King of Random, examines 3 DIY recipes for different kinds of invisible inks.

Lemon Juice

The idea behind this one is that if you squeeze out some lemon juice and then use a stylus or quill to write a secret message that the recipient can place the message over a heat source and the words will magically appear. The trick of course is to do this without burning the paper!

Baking Soda and Water

This method uses baking soda and water as the “ink” using a 1:1 ratio. Grape juice is then used as a special agent to reveal the secret message. A heat source can also be used to make the “ink” show up.

Bleach

Using undiluted chlorine bleach to write with, the theory is that the ink will clearly show up when placed under a UV light. When a UV light is held over bleach sitting on a plate, nothing much seems to happen. But, what about when the chlorine bleach “ink” has dried onto paper?

Always be careful when using bleach as touching or inhaling it can cause skin and breathing problems.

So which method works the best? Watch the video below to find out. Each method has its advantages and disadvantages, but this looks like a really fun experiment!