Some people have attempted to remove pen cancels from used stamps in order to turn them into more valuable unused stamps.

Excellent proofs and a complete set of unused stamps will be overshadowed by invert errors.

Arthur de Rothschild (1851-1903, Belgium), collector of unused stamps issued between 1860 and 1880.

There are typically two parts to the process; first, the exchange of unused stamps for new ones of equivalent value.

Why, all anybody would have to do with unused stamps would be get them canceled and boost the price.

Only what's to prevent a collector from shipping some unused stamps back to the country where they came from and letting some friend mail them?

They are highly coveted by collectors, and the rarest - an unused 2-cent stamp - was sold in 1995 for $660,000.

You must return any unused stamps to our contractor if you are deregistered.

If you are acting on behalf of a registered person, you must return unused stamps to that person.

The Swedish government had the unused stamps destroyed; these scarce items are now eagerly sought collectibles.