Rarity, in card collecting, is a relative term, modified by a multitude of considerations. The most basic meaning would infer only one or very few in existence. As an example, an actual photo card is rare by its very nature. Only one of each was made. Typically, a box camera in the early 1900s was used to photograph a scene. Then, the negative was used to make one copy of the picture on postcard stock.....thus, an actual-photo card. If multiple copies had been made by a card producer, it would have
been called a real-photo card.

To continue with our discussion of rarity, let's assume that someone in the early 1900s took a picture of a small pond and had an actual photo postcard made of it. Over time the postcard ends up in someone's collection. It is an extremely rare card, because only one was made.

The question now is; is it collectible? Let's put it this way.....would you pay $5 for an actual photo postcard of an unidentified pond with no information as to when or where the picture was taken? If you would, please contact me. I've got quite a collection of rare cards of that type. However, information about a given card increases its value. If the person who took the original picture had dated it and detailed the location as "The pond in back of the John Doe residence in Hometown, USA" and the current owner found that the property had been converted to The Hometown Mall, it would have historical, and perhaps personal, interest.

When we think of rare cards in postcard collecting, we assume much more than basic rarity. We think of the desirability of an image: its beauty, when it was made, what it represents, how fully it represents what we look for, how available it is, and how much it costs. These considerations, plus hundreds more, constitute what we really mean by the term "rare".

I collect rare airline postcards. But what is rare to me may not be rare to someone else, and what is rare to someone else may be very common to me. There are many postcard producers that currently make, or in recent years made, airline postcards. These producers include: Aironautica, Avia Products, Aviation World, Inc., Avimage, DPR Marketing, Editions JP, Flite-Line Fotocards, International Airlines Museum, International Airline World Publishing Co., Manche Postcard, Mary Jayne's Railroad Specialties, O.K.C. Praha, Plane Views, and Team-Druck. There are many more.

The advantage to the collector of such producers is the abundant variety of readily available cards at inexpensive prices. While you may see such cards at postcard shows priced at $2 or $3, most of those same cards are available at under $1 directly from the producers. To me, a card that is readily available at inexpensive prices cannot be considered as rare.

As producers of such cards recede backwards in time, the cards themselves become more collectible. John Proctor, a contemporary pioneer of mass-produced airline postcards for the collector, stopped producing postcards under Aviation World, Inc. in 1986 and under Flite-Line Postcards in 1988. A few collectors of "modern" airline cards are trying to collect the entire line of Aviation World, for example. To these collectors, a card they don't have may seem "rare".

So the term "rare" is relative to what one collects and what that collector already owns. I like to collect airline postcards that pre-date most of what I call the "subscription airline postcards", which are those listed a few paragraphs ago. But even then, my collecting interests are not well-defined. American, Eastern and United Airlines each produced and distributed postcards showing their aircraft during the '50s through the '70s. Some of their cards were produced in prodigious quantities, making such cards readily available 40 years later. These cards, to me, are not rare. However, some cards produced by these giants are rare.

The only way I know how to determine whether an airline postcard is rare or not is to spend a couple of decades collecting, buying, and selling such cards. Experience is the best teacher, but is not infallible. So when someone contacts me about an airline postcard, I usually require a detailed description, an image (attachment, photocopy, scan, fax, etc.) or the card itself on approval.

The best way is to receive the card on approval so that it can be examined for condition (which is very important), publisher, age, availability, subject matter, demand, and appeal. All these criteria are discoverable by experience. And all these criteria help to determine rarity.