In the first U.S. stamp application of thermochromic ink,[6] the Total Eclipse of the Sun Forever stamps reveal a second image. By rubbing a thumb or finger on the image, the heat imparted will cause an underlying image of the full moon to be revealed. Afterward, the image reverts to the dark image as it cools.
The US Postal Service notes that exposure to ultraviolet (UV) light causes degradation of thermochromic inks, so the eclipse stamps should be shielded from sunlight to preserve their thermochromic behavior. To help with this, the Postal Service sends panes of this stamp to purchasers in special UV-blocking envelopes.[7] In addition, UV-protective sleeves for the eclipse stamps are available from post offices for 25¢ each.
The stamp is a Forever stamp so has no defined denomination which means it will always be equal in value to the current First-Class Mail 1-ounce price, regardless of any future rate changes.[12]
First day ceremony
The stamp's First-Day-of-Issue ceremony took place on June 20, 2017, at the University of Wyoming's Art Museum in conjunction[15] with its annual summer solstice celebration. That building was designed with an architectural feature whereby, on the day of the summer solstice each year,[16] a single beam of sunlight moves across the floor[17] and shines on a silver dollar embedded in the floor in the center of the Rotunda Gallery at noon.
^"Eclipse America". American Astronomical Society. 2017. Retrieved 2017-07-18. For the first time since 1979, a total eclipse of the Sun is coming to the continental United States, and for the first time since 1918, it is crossing the country from coast to coast.
^Loison, Faustine (2017-05-24). "L'encre thermochromique qui éclipse le soleil" [Thermochromic ink that eclipses the sun]. GraphiLine.com (in French). Retrieved 2017-07-18. Ce timbre qui est le premier timbre américain qui utilise de l'encre thermochromique [This stamp is the first American stamp that uses thermochromic ink]
^"Sonnenfinsternis in den USA am 21. August: Wo die Sicht am besten ist" [Solar Eclipse in the USA on August 21: Where the visibility is best]. Der Spiegel (in German). 2017-06-10. Retrieved 2017-07-10. ... hält die US-Post bereit: Sie legt eine spezielle Briefmarke auf, die 'Total Solar Eclipse Forever'. Berührt man die auf der Marke abgebildete verdunkelte Sonne, erscheint ein Bild des Mondes. Das Foto auf der Briefmarke zeigt allerdings die Sonnenfinsternis vom 29. März 2006, aufgenommen in Libyen. [... the US Postal Service is ready: it is making a special stamp, the 'Total Solar Eclipse Forever'. If one touches the darkened sun on the stamp, a picture of the moon appears. The photo on the stamp shows, however, the solar eclipse of 29 March 2006, taken in Libya.]
^"Stamp Announcement 17-27: Total Eclipse of the Sun Stamp". United States Postal Service. 2017-05-11. Retrieved 2017-07-12. On June 20, 2017, in Laramie, WY, the U.S. Postal Service will issue the Total Eclipse of the Sun stamp (Forever priced at 49 cents), in one design, in a pressure-sensitive adhesive (PSA) pane of 16 stamps (Item 475300). The $7.84 Total Eclipse of the Sun pane of 16 stamps may not be split, and the stamps may not be sold individually. The stamps will go on sale nationwide June 20, 2017.
