Mostly they were from US.
Why are they uncancelled ?
Celebrity paid other postage ?
Post Office just forgot cancel it?
Or-Are they cancelled with invisible ink ?
As Japanese post office use invisible ink for New year cards
(We send new year cards rather than Christmas cards, by the way).
I've ever heard that those invisible ink can be seen by Black-light.
And also I'd like to know:
Do you guys use those stamps again?
