Cool version of the stamp.
Heated version of the stamp.
The solar eclipse of August 21, 2017 was a total eclipse visible within a band across the entire contiguous United States, passing from the Pacific to the Atlantic coasts. As a partial solar eclipse, it was visible on land from Nunavut in northern Canada to as far south as northern South America. The United States Postal Service issued the Total Eclipse of the Sun Forever stamp on June 20th. This is the first U.S. stamp application of thermochromic ink. By rubbing a thumb or finger on the eclipse image, the heat thereby imparted to it will cause an underlying image of the full moon to be revealed. Afterward, the image reverts back to the eclipse as it cools.