Postcards should be individually encased in a sleeve of a type which will not damage the postcard. Then the postcards should be placed in an enclosure which permits the postcards to stand on edge.
Postcards should not be placed flat for storage. The pressure can cause the picture surface to come loose in chips or flakes.
If suitable for the purpose, postcard pages can be used in a notebook where the notebook is stored in an upright position, never flat. And each binder should have the slightest amount of space to move to each side so as not to pack them together and cause possible contact transfer. An album is typically not suitable for most collectors since the space needed to store the postcards would be huge.
An excellent method of storage in air-conditioned environment is a file cabinet. Here is a picture of the cabinet I use.
Each drawer will hold 500 or so postcards. They are all on edge. If 500 seems like a lot of cards to have, don't laugh. My collection is probably 20,000. None are valuable except to me. I frequent the 25 cent boxes and buy mixtures. I do not have expensive taste in postcards. I have paid as much as $35 for an Eiffel Tower Hold-To-Light. That is where my extravagance ended.
In each drawer there can be alphabetical dividers to organize cards in a category. Here's a sample of how a drawer with A B C dividers looks. I do this with my Germany, Switzerland postcards. They are arranged by cities.
Just as books need a constant environment for proper storage, postcards need the same tender loving care. They are made from paper too.
So never store postcards in a space that gets really hot or really cold. Spaces with high humidity are also a poor location to store your postcards.
Avoid closets where thee is no air circulation. And be sure not to place your storage boxes under areas where leaks from above may come down and destroy your collection.
This all means that your postcards should live with you in the space you occupy. You don't live in the garage, attic, basement, shed or storage locker. Your postcards shouldn't, either. Postcards are your friends. Any space that is temperature and humidity controlled should be fine.
Regularly check the condition of your postcards.
Bug spray around the space may be needed if insects are present.
And then there is the matter of theft. Probably not too many people would break in to steal your postcard collection. It is bulky, hard to sell, and just isn't worth that much. So reasonable care seems enough. If you do have a collection that is valuable in dollars, not just sentimental value like mine, then you may want to consult with your insurance agent to see if there is some extra premium which can be paid to cover your postcard collection. My collection would probably require a premium of more than the cards are worth in dollars. So there is no reason for me to insure the postcards.
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