Ever wondered whether all these commemoratives issued by postal services are really used postally? Of course you have, as a collector you simply can’t have missed all these (expensive!) series of commemoratives being offered from all over the world. Do places like Saint Vincent & the Grenadines, Tuvalu or Vanuatu really need so many stamps? Yes, of course you are right: these are almost always being issued just to sell them to the (new) collector. You’d be lucky to find them used on a real cover. But that doesn’t mean they are never used.
Here is an example I received in early August 2018. The stamps are two of the stamps from the series “Sounds of Korea” (KPC3276-3278). This series was published on 30 April 2018. It was listed on the KSS website of course. I had not expected to see the actual stamps used on cover however. But there they are:

Of course, technically speaking this is still a “philatelic cover”, especially since the cover was sent by a Korean stamp dealer (Ebay seller: primechoice7). What I did notice however are the colours used on the stamps. You can’t see it in the scan (or in the artwork as shown in the original listing) without actually holding the stamps in the light, but the gold and silver in the pages light up quite nicely when you move the cover about.
If you have a recent piece of postal history please send in your materials!