Secret writing craft using lemon juice, milk, starch, or phenolphthalein for ink!

Amaze your friends by making a message appear on paper as if by magic!

Here is what you need

A clean penpoint (nib) and penholder. This is the type of pen. You may have to purchase one from the stationery store if your parents don't have one. If you buy a new one, be sure your parent or teacher holds the nib over the flame of a match to burn off the oil, allowing the point to retain the ink.

Lemon juice

A small flame, such as a match or candle. DO NOT light matches or candles without the help of your parent or teacher!

Notepaper or stationery to write on

Milk

--from a medicine called Feen-A-Mint

Saucer

Soup bowl

Medicine dropper

Rubbing alcohol

Spoon

Soapy water

Ammonia--Only parents or teachers can handle ammonia

Iodine--Only parents or teachers can handle iodine

Starch

Glass full of boiling hot water--Only parents or teachers can handle boiling water

Soup bowl

Instructions

1. Fill your pen with lemon juice and write a secret message on a page of paper. The secret writing will be invisible. Now, ask your parent or teacher to carefully heat the page over the flame of a candle--being careful to not let the paper get too hot or it will burn! Your secret message will appear as if written in brown ink!

2. Wash out the pen and refill it with milk instead of lemon juice. Now write a secret message and then make it readable just like you did with the lemon juice writing. Simply amazing!

3. Make a solution out of the Feen-A-Mints or any laxative that contains phenolphthalein by crushing it as fine as possible with the back of a spoon in the well of a saucer. Then add a little of the alcohol to form a test solution. Allow the mixture to settle for a moment. Wash out the pen and refill it with the phenolphthalein solution and write a secret message on your paper. When dry, the secret writing will be invisible.

Dip the paper in soapy water or ammonia and see what happens!

Or sponge the paper with a paper towel dipped in ammonia. What do you see?

In what color does the writing appear?

Why does the writing disappear again?

4. Ask your parent or teacher to make a secret ink by stirring a spoonful of starch in a glass of boiling water. This ink will also be invisible when dry. Now wash out your pen and refill it with this invisible ink and write your secret message.

Now put ten drops of iodine and a half-cup of water in a soup bowl and stir. Dip your secret message into it.

Do you see your message in blue? Did the entire page turn blue also? What do you think is in the paper to make it also turn blue?


Back to Chemistry For Kids page from Secret Writing page

Back to Kids Crafts page

Back to Kids Craft Index page