Did you know you could use the juice from a lemon to write a secret message? Materials: Instructions: STEP 1: Squeeze the lemon juice into the plate. STEP 2: Dip the cotton swab into the lemon juice.

When I was a kid, my friend had this pen with invisible ink. You could write a note with it and then the person you sent it to had a different pen that made the text show up. We though it was awesome ...

EFFINGHAM COUNTY, Ga. (WTOC) - In this Summer Science experiment students at Effingham College and Career Academy show us how to create invisible ink using a lemon. - When the lemon juice is heated a ...

Turning the childhood invisible ink trick on its head, this mod from Make allows you to print out invisible messages with your inkjet printer. Matt Richardson put together this excellent video with ...

William Abel, a mail censor at Iowa's State Prison, Fort Madison, using a hot iron to bring out a secret message written in lemon juice on a letter.Three Lions/Getty Images Humans have had a long ...

A letter from the Revolutionary War with lines written in invisible ink. Credit: Wikimedia Commons Last year, the US Central Intelligence Agency released documents detailing recipes for invisible ink ...