An exceptional phenomenon - on a global scale - was the Solidarity underground mail. The first special stamps, post cards, and envelopes were created in internment camps. With time, they began to be printed by the underground structures. The stamps, which frequently had a considerable artistic value, soon became the envy of collectors. Apart from their propaganda role, they were of considerable importance in the process of gathering funds for underground activities. Today, they are a fragile, albeit beautiful, reminder of those difficult days.