We'll have another one of those: can you spot the difference?
This is stamp A.
And this is stamp B.
No, I didn't think you could! Neither could I before last night. But that is the great thing when you go beyond your standard world catalogues: a whole new world opens up before your eyes!
And that's how I found out that Australia has a rather unusual way of applying phosphor to stamps. Most countries just have bars or all-over phosphor, but on many Australian stamps the phosphor is applied to certain parts of the design, like an animal or plant. And when you then got different formats (and sometimes different printers) like coils and booklets you sometimes get different phosphor layouts, like on the stamps I showed you.
Admittedly, you do need some equipment for this but who could be without a UV-lamp anyway?! Go and sort your Australian kiloware (there's lots of it about!) and see what treasures you can come up with!