Invisible ink
Invisible ink is a fun way to to send a message - or make a secret note that you can reveal later.
On a more serious note there is some interesting chemistry behind each of these reactions.
Normally we practice using:
- plain white paper - to carry the message.
- an earbud or tooth-pick as the pen.
- the secret ink.
Once the message is written and allowed to dry... it looks just like a plain page of paper.
To see the message you need to develop the ink, normally through a temperature chemical action.
Invisible inks
Some of the inks could be:
- Baking soda and water
- Lemon juice
- Milk
Use the ear bud as a pen. Dip it in the "ink" and then write on the paper then allow the "ink" to dry.
Display the message
Applying gentle heat to the white paper will reveal the message in the case of baking soda, lemon juice and milk. Gentle heat could be warming the paper
- over a light bulb or a candle flame
- warming the paper with a clothes iron