1 Tablet of laxative
1 tbsp Rubbing alcohol
laxative tablet into the tablespoon of alcohol. Be sure the tablet is
entirely dissolved. Write a message on the paper with paintbrush dipped
into the solution. As the solution dries, the writing will disappear. To
develop the message: dampen the cotton ball with liquid ammonia and dab it
on the page. The writing will reappear.