Exactly, Prue, I was going to say that there is a ratio between the two sides that can usually indicate a cabinet card vs. a carte de visite. That said, I've heard that cartes de visites, while exceedingly rare after 1900, did indeed exist up to the 1920s or so. I think this can be chalked up to old photographers who either didn't have the money to update their equipment or didn't want to - the same way that there are film and Polaroid enthusiasts. It's an unusual carte de visite, but not impossible.