Science Experiment Invitations
Write out your invitation to it resembles a science experiment.
Purpose: To have a (birthday, Halloween, etc.) party.
Hypothesis: Mad Scientist parties are more fun than other types of parties.
Information: Should your guests bring anything? Will they be getting slimed or should they bring swim suits? Dry ice or liquid nitrogen in the pool is great for an adult party, though it is not a good plan for kids.
You are welcome to print out and use this silly picture of Einstein or the mad scientist. Don't forget that many scientists, mad or otherwise, can get email, so you may be able to email the invitations instead of mailing or handing them out.
Test Tube Invitations
Write your party details on strips of paper and then roll them to fit inside inexpensive plastic test tubes. Hand the invitations out personally.
Invisible Ink and Secret Message Invitations
Write your invitations using any of the invisible ink recipes. Explain on the invitation how the message can be revealed.
Another option is to write the message using a white crayon on white paper or a white card. The message can be revealed by coloring the card with a marker or painting it with watercolor. This type of message may be easier to read than the type produced using invisible ink.