In the first ever use of thermo chromic ink on a US postage stamp, heat from a finger when touched will expose a different image on the face of the stamp. The back of the stamp will feature a map of the eclipse path and times it will appear in major cities.
The stamps are a tribute to the upcoming solar eclipse that should occur August 21st. Press your finger to the stamp and your body heat will transform its black circle centerpiece into an image of moon our . Once the heat dies down, the stamp image goes back to black. While it’s not as elaborate as you might think, this is something that’s sure to make philatelics smile.