How to Make Disappearing Ink Reappear

You can't always see ink like this.
••• bottle of ink image by Alfonso d'Agostino from Fotolia.com

Imagine that you have received a note from a friend, or perhaps, intercepted a message from an enemy. But the paper appears to be blank. Well, fear not. If the message is written in disappearing ink, a few simple steps can reveal the hidden communication.

    Apply heat to the paper. Use a 100 watt light bulb, an iron or a blow dryer. If the disappearing ink is an acidic or organic substance such as lemon juice or milk, the paper will burn at a different rate than the ink, revealing the spots where the secret ink lies.

    Apply a chemical reagent such as lemon or grape juice with a brush, sponge or cotton swab. Experiment on a small portion of the page to see which reagent works best. For example, if the invisible ink is a baking soda solution, acidic grape juice will react with the sodium bicarbonate, revealing the message in a different color. You can try apple juice, lemon juice, vinegar, grape juice, white wine and many other acids.

    Rub salt into the disappearing ink. Wait a minute and then brush the salt off the paper. To reveal the message, write over the page with a wax crayon.

    Things You'll Need

    • Heat source
    • Juice
    • Vinegar
    • Cotton swab
    • Brush
    • Sponge

    Warnings

    • When heating the page, be careful not to ignite the paper. Do not use a halogen lamp because there is a greater fire hazard.

Related Articles

How to Separate Ink From Water
How to Remove Iron Filings From Magnets
Experiments With Salt and Vinegar
What Color Would a Tester PH Paper Turn if Is Dipped...
3 Fun Experiments to Do While You're Stuck at Home
The Properties of Acidic Substances
Science Fair Experiments With Baking Soda & Water
How to Make Ozone Test Strips
Test Your Knowledge on Middle School Science
Experiments on Cleaning Pennies
How to Dissolve EDTA in Water
What Chemicals Rust Metal Rapidly?
How to Make Flash Paper
How to Make Homemade Glow Sticks
How to Make Forensic Luminol
How to Identify Bees, Wasps & Hornets
Paper Chromatography Science Projects With a Hypothesis
How to Neutralize an Acid
Why Does Lemon Juice Turn Paper Brown?