A philatelist is a stamp collector. In order to remove stamps from envelopes or packages, philatelists have developed an efficient technique of soaking the stamps in water. This effectively removes most stamps, including modern self-adhesive stamps, causing little to no damage, as long as the procedure is followed and care is used. Above all else, avoid touching the stamps with your fingers or laying them directly on any surface but a stamp book or clean paper; the oils and dust from your fingers or other surfaces might damage the stamp.
Set aside all stamps with coloured cancellations, dark-coloured stamps, stamps on coloured paper and stamps with strange-looking ink or poor quality paper. These stamps will have to go through the stamp removal process individually to ensure they don't stain other stamps or become stained themselves.
Trim around the postage stamps, leaving an approximately 5mm border around the stamp. Be careful not to damage the stamp itself.
Fill one shallow, wide bowl with several inches of lukewarm tap water. Make sure not to use hot water; in a very few cases you may need to use hot water on self-adhesive stamps, but this is the extreme exception and should be done only on an individual basis. Fill the other bowl with a similar quantity of cool water and set it aside for now.
Using stamp tongs, place the stamps--as a group if you didn't sort them out in Step 1, or individually if they were set aside--in the lukewarm water, face down. If they try to flip right side up, carefully turn them over again with the tongs. If you're placing the stamps in a group, make sure that there's plenty of room for all of them in the bowl; ideally, they shouldn't overlap at all.
Let the stamps sit in the water for five to ten minutes, then agitate the water gently to see if any stamps are ready to separate from the paper. Once stamps separate from the paper they will drop to the bottom of the water, at which point you can remove them with stamp tongs and place them, face up, in the tub of cool water.
Persuade stubborn stamps to come off the paper by grasping the paper backing by one edge and swirling it around in the water. If the stamps still won't come off, let them soak longer--some self-adhesive stamps may need to soak for up to an hour before the glue softens. You can carefully peel the stamp away from the paper, using stamp tongs, only as a final resort. Once you have the stamps free, place them in the cool water as directed in Step 5.
Remove the paper-free stamps from the tub of cool water, using stamp tongs, and gently rinse the back of the stamp with cool water from a bulb syringe. Lay the stamps face up on white paper or in a special stamp drying book (available from stamp collecting shops) to dry.
Don't try to soak United States World Stamp Expo 2000 hologram stamps; the water will damage them. Instead, trim the backing paper away from the stamp edges as carefully as possible.