Have you ever wanted to write something for someone but you don’t want anyone else to see it? A secret message that you want kept secret, but you don’t know how to achieve it? Invisible ink is the answer and it is very easy to make.

Invisible ink can be made from a great number of organic fluids (milk, lemon juice, white wine, onion juice etc). Here’s how to do it;

All you need is a small glass of whatever liquid you have chosen to use, something to write your message with and a sheet of paper. Dip your writing tool into the ‘ink’ and compose your message on the paper. It really is that simple. Once the liquid has dried into the paper it will be invisible to the naked eye.

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If it is invisible, how can the recipient read it?

It is all about heat! Putting the paper into a heated oven, using a hot iron, or even holding the paper over a candle-flame will result in the ’secret’ message revealing itself. The reason it works is because the organic fluid has a lower ignition temperature than the paper and thus will start to burn first (revealing the message).

Keep in mind that using smooth or glossy paper is not the best thing to do as it doesn’t allow the liquid to soak into the paper too much. If you are going to write a ‘dummy’ message over the ’secret’ message to hide it further until the heating, use a ballpoint pen or a pencil; don’t use a fountain pen as the ink is thicker and may run too much through the paper, ruining the secret message.