Invisible ink

Invisible ink We know that phenolphthalein will turn pink if you drip 2-3 drops into a chemical that is base. That gave me an idea of how to make invisible ink. Things you'll need: phenolphthalein solution, white paper, Q-tip, and ammonia-based glass cleaner (like Windex) Put a few drops of phenolphthalein onto a Q-tip. Use the …