
Ingredients and Supplies
¼ cup baking soda ¼ cup water Grape Juice Paper Something to write with- a cotton swab, toothpick, or paintbrush all work well.
Recipe courtesy of the book Invisible Ink: Spycraft of the American Revolution by John Nagy
¼ cup baking soda ¼ cup water Grape Juice Paper Something to write with- a cotton swab, toothpick, or paintbrush all work well.
Recipe courtesy of the book Invisible Ink: Spycraft of the American Revolution by John Nagy