Cover and stamps from USA

My first post for this year is about a nice cover from USA with some really nice mint stamps inside, but stamps on cover are also very nice:
Butterflies - Eastern Tiger Swallowtail, issued on 01.06.2015.
Hanukkah, issued on 19.11.2013.
Year of the Snake, issued on 16.01.2013.
Holiday Windows (from set of four) issued on 06.10.2016.
WPA Posters (from set of ten) issued on 07.03.2017.
Flowers from the Garden (from set of four) issued on 16.08.2017.
Definitive - Red Pears, issued on 23.03.2017.
Chopper c.1970 (from set American Motorcycles) issued on 07.08.2006.

The Total Eclipse of the Sun stamp is the first U.S. stamp to use thermochromic ink, which reacts to the heat of your touch. Placing your finger over the black disc on the stamp causes the ink to change from black to clear to reveal an underlying image of the moon. The image reverts back to the black disc once it cools. This wonderful stamps are issued on 20.06.2017.

The back side of this sheet is also interesting, it shows the path of the eclipse that occured on August 21, 2017.

I've found this awesome gif which shows you how this thermochromic ink works.

I also received this beautiful set Have A Ball! Eight circular stamps showcase some of the sports balls used daily in the United States: baseball, basketball, football, golf, kickball, soccer, tennis, and volleyball. A special coating applied to selected areas of the stamps during the printing process gives them a textured feel. Stamps are issued on 14.06.2016.

I also received pair of one more rounded stamp: Green Succulent, issued on 28.04.2017.


Thank you very much Charlotte!