• Use lemon juice and a paint brush to make designs or words on paper.
• Allow it to dry.
• When you want to see the invisible message brush a dilute solution of iodine and water on the paper.

The iodine will complex with the starch in the paper and turn purple. The lemon juice painted sections will remain white. Caution: Iodine will stain almost anything it touches brown and is not an easy stain to remove.

Don't have any Iodine? Try this:

Children must be very be careful and ask the help of an adult to do this!

Want to try something else? Try making a "normal" ink from tea...