Invisible Ink


What You Need:


While the paper gets heated, the letters written with the invisible ink become visible as the ink gets dark. Lemon juice is an organic substance that oxidises and turns brown when heated. Diluting the lemon juice in water makes it very hard to notice. Invisible ink can also be made using certain chemical reactions or by viewing certain liquids under ultraviolet light. You can use orange juice, honey, milk, onion juice, vinegar or wine instead of lemon juice to prepare invisible ink.