King George’s Invisible Signature
In this episode of SPY's Collection Highlights — H. Keith Melton showcases rare invisible signatures of King George and Queen Mary.
Resources
Spy from Home: How to Make Invisible Ink
The International Spy Museum shares fun and engaging out-of-the-box activities while you and your kids are at home.
Invisible Ink Formulas
Explore a variety of invisible inks that you can use at home. Afterwards, try the secret message egg challenge!