Total Solar Eclipse 2024

Total Solar Eclipse 2024 cover from Columbia, Ohio

This cover was posted on 8th April 2024 from Columbia, Ohio

Path of 2024 Solar Eclipse

Path of 2017 and 2024 Solar Eclipse

My 2017 Solar Eclipse cover

USPS's First Thermochromic Ink stamp

USPS's First Thermochromic Ink stamp

USPS's First Thermochromic Ink stamp was released on June 20th, 2017 to commemorate the August 21st Total Eclipse of the Sun.  The stamp has a black circle in the middle, when it is exposed to light/heat the image of the moon will appear.  Thermochromic inks are vulnerable to UV light and should be kept out of direct sunlight as much as possible to preserve this special effect.  Since the stamps on the cover are traveling a long way, they are exposed to sunlight and obviously they lose their special feature.  In order to preserve the Mint stamps, USPS is providing some special envelopes at an extra cost.

Thanks a lot Arakan, USA for sending these stamps on the cover.

Renewable Energy II: Liechtenstein Post

Renewable energy sources are mainly the Sun, Wind and Water. Today's conventional energy sources may exhaust one day but renewable energy is not depleted upon usage. It is natural, harmless, economical and good for the environment.

Liechtenstein Post has issued two series of renewable energy stamps, one in 2010 and the other in 2011..  Below is the second series of renewable energy stamps.  I heard that they used Thermochromic ink in this stamp and if you apply heat on the area, the colour will change. 

But I couldn't see the change at all.  I purchased it from Liechtenstein Post directly.  Is there anything like only in miniature sheet it will work or any other hidden thing.  If anybody know the answer please clarify.