INVISIBLE INKS
Use any one of the following to write your message on plain white paper. 7-Up Apple juice Milk Or mix together 1 teaspoon sugar or salt and 2 teaspoons water. After you've written your message using a cotton swab, paint brush or your finger, let it dry completely. Then have your friend hold the paper over a hot light bulb (but not too close). Your message will turn brown and then your friend can read it.