Posted By:
davidcyclebackI'm not knowledgeable about this issue, but self developing photo cards usually came as a kit-- envelope, negative, paper, etc. These may have been cataloged as self developing cards, as someone out there has seen the kit. A number of the self developing kits are obscure and are rarely seen on the market. That none of us has seen the kit, or even a picture of the kit, doesn't neccesarilly mean much. Some of the self developing photo kits had both baseball and non-sport cards (actors, etc), so some of the knowledge for these sets may have come from the non-sport hobby.
There's no question that these cards are much better developed than many other self developing photos. Which is a good thing.