Coincidentally my mail art colleague Cascadia Artpost sent me a stamp from the USA recently (received yesterday!), including all three items in one.
A stamp, issued in honour of the solar eclips which will be seen on 21st of August, mainly in the USA.
Three in one? Yes: the sun (a star), more or less hidden by our moon (the moon), seen from the earth (a planet).
The technique used for this stamp is - as far as I know - new in its use for stamps.
The mechanism is used for mugs, but now it isn't warm tea or coffee which reveals the image, it is the warmth of our own finger. Fortunately Cascadia added an instruction manual to it, as you see above.
When warmed up, you can see the moon!
See more stamps on stars, moon, planets at and via today's Sunday stamps.
