We like to claim that the rate of change in the world has sped up in recent years. But the 20th century started with astonishing changes, too.
In 1898, copyright laws were changing, defining what protections existed for creators of poetry, music, art, books, and images. When a work was properly registered with the Copyright Office, the creator was supposed to be protected from the theft of his work. (Yeah, that didn't work much better in those days, either.)
Postcards were usually a penny to buy and a penny to mail, and collecting "postals" was a craze until about 1920.
What Is the Origin of the Real Photo Post Card?
Cameras were becoming portable, but not exactly cheap. Roll film was developed. Kodak created pocket-sized folding cameras that got lots of folks interested in photography, and then larger models that exposed 3.25" x 5.5" film—just right for postals. Of course, Kodak then started selling photo emulsion paper that was just the right size and stamped "Post Card" on one side.
Postcards produced from this large film are usually very sharply defined. The film was laid on the paper, exposed and developed. There was no opportunity for light (composed of those silly little wavicles) to bend and scatter and soften edges, as happens in enlarged images. This level of definition had previously been the a hallmark of professional photographers with their big plate cameras and carefully timed exposures.
These are what we most often call Real Photo Post Cards, or RPPCs.
The Role of the Post Office
The post office, using lots of fairly cheap labor, was excellent at collecting and delivering mail. A network of railroads, built over the previous 50 years, carried mail over long distances. Some trains had their own Railroad Post Office (R.P.O.) postmarks.
The Instagram of Its Era
In an era when even newspapers weren't regularly printing photos, people could create their own photos and post them to relatives and friends. The subjects ranged from baby pictures to family reunions, from Christmas cheer to funeral gatherings, and from houses that distant relatives might never otherwise see to disasters like floods or fire. Amateurs and professional photographers alike embraced the real photo postcard. When World War One started, soldiers and sailors sent home images of troops, ships, and foreign battlefields.
Going into the 1920s, the fad of collecting postcards passed. Photographers who had made a living producing RPPCs for 20 years had to find new ways to market their photos or leave photography completely. The cards were often tucked into boxes and albums, saved for us to enjoy a hundred years later.
How to Identify a Real Photo Post Card
If you have a magnifying glass of 10x or so, it's easy. Photos don't have dots. Printed images do.
RPPCs start their lives as black and white film images, but waterbased paints were sometimes applied. These may be called "hand-tinted" and would add color to faces or skies. Older RPPCs won't be on bright white paper. There wasn't as much bright paper to start with before the 1930s, and chemicals used in developing would yellow them a bit.
One of my favorite ways of identifying photo postcards in a collection is that they tend to bow. Developing a photograph involves water and the paper wants to curl after it's been wet. Cards stored in an album may not have a curl.
Other clues are the migration of silver to the surface of the image. Over time, the emulsion is separating and an odd sheen appears, usually on dark areas of the photo.
Real photos can fade, either from exposure to light or poorly fixed emulsion.
A lack of any kind of identification is also common with real photo postcards. Though it was possible to mark a negative, most RPPCs were sold locally or mailed to people who knew what they were seeing. Identification of people or dates was unnecessary. Another annoying historical quirk that arose was the cost of postage. It cost a penny to mail a postcard, but only two cents to mail a letter. So folks would often put one or more RPPCs in an envelope with (or without) a letter and mail them that way -- leaving no postmark on the cards.
Real photo postcards were produced into the 1950s.