Your ink may seem invisible when you're writing your secret message, but the pen is actually leaving a residue of sodium bicarbonate (aka baking soda). When you rub your paper with a berry or tea bag, the acid in those items creates a chemical reaction with the baking soda, a base. That reaction makes your message become visible. General information: One supplied. For ages 6 years and over.

EAN: 35051539179.

WARNING(S): Not suitable for children under 3 years old.

Only for domestic use.

To be used under the direct supervision of an adult.

This toy does not provide protection.