Text messaging is so yesterday! How about sending a friend a note the old fashioned way? By writing it - Using Invisible Ink! It's simple, easy and fun.
All you need is some milk and a cotton bud (Q-tip). And, since it is technically science, your parents will be thrilled that you are doing something useful for once!
The Fun And Easy Part
Pour a little milk (full fat will work best) in a bowl. Dip the Q-tip (you can also use a toothpick or an inkless fountain pen) in the milk and start penning your letter on a white piece of paper. Be sure to know what you are writing, for you will not be able see any of your words against the white background! Let it dry for at least 30 minutes.
When ready, send the seemingly blank looking paper to your friend(s). All they have to do to read your secret message, is press it with a lukewarm iron and voila, the words will start to appear.
The Science Part
The fat in the milk starts to burn much faster than the paper and turns dark brown, clearly revealing all the words against the white surface of the paper.
Like It? Try it and let us know if it worked!
source: desicolours.com