Used stamps exchanges.

never overlay self adshieve stamps, pls
5 stamps are damaged on envelope and there is enough space

Excellent idea. The top two will be OK but any underneath are spoiled as far as collecting is concerned. sometimes I get Canada self adhesive overlapped and I just take the top one and throw the other one away. They just will not clean.

Hi friends,
it is very sad that collectors remove stamps from envelopes. The envelope with stamps is much more valuable than just separated stamps on it. And I don´t mean only the value for collectors, I mean also the financial value on the market. I always send my lots as registered letters with nice stamps and it is something like "murder" in my point of view, if you remove the stamps and destroy the cover.

If there's any possibility; try to avoid using such a common stamps for postage. All countries issue great stamps that are much harder to get. Use those instead if you have the chance.