Valid Stamp?

[birdsatemylunch]

That Energy Awareness Month one…

[S_Tuulia]

@LC-Canada

but apparently there may be an invisible cancellation mark that only sorting machines can see. And if you were to use the stamp again, it might get sorted out of the system.

Little off topic, but for about ten years ago there were rumours about these type of invisible cancellation in Finland. But, when you think it, what would be the point in that? To lure people in reusing stamps, and then catch them? And, when they don’t always succes to use the normal visible postmark, I don’t believe they have a different postmarker to use that for some mail, and then hope (?) the reusers happen to choose just this stamp for reusing purposes, that is stamped with invisible ink.
I think it’s just an urban legend. (Unless they mean the light neon orange version, which is visble, but not as good as the usual black/dark).

Edit. I’m actually interested, if this invisible cancellation -thing is told in many countries?

[LC-Canada]

No, it’s not an urban legend apparently, it’s just high tech, nothing about luring anyone, it’s just what state the tech is in now

[S_Tuulia]

But why use invisible ink? In addition to the visible? Are stamp collectors supposed to buy equipment to see the marking? Or is this a secret that no one should know about .

[LC-Canada]

It’s just the tech, beyond that, I don’t know the motivations & there may not be any - tech design often has no human logic

[S_Tuulia]

Doesn’t convince me. Of course there should be motivation as they should pay for this kind of extra work, in machinery and workforce. I don’t think they would do this out of boredom.

When, think: post office arranges equipment for invisible postmarking, and uses special ink to that.
In addition they need equipment to detect these from all the mail. Do they postmark every item with invisible ink, or selected ones, and how are the ones selected? Then, to find the possible reuse, they should check all mail with postage stamps, to find if someone has put a already used stamp? Why all this, when they could only use the traditional visible ink, to prevent the reuse. I still think it’s urban legend.

(With this I don’t mean to encourage to reuse stamps.)

Edit. now I tested this. The neon orange barcodes are better visible with UV light, but nothing more, no extra invisible marks in postage stamps received from Finland, The Netherlands, Canada, USA, UK or Spain (but how many clear postage stamps ).