[griffon512]

To start, if one can't definitively say whether a card is coming from a bread package or a Sports Star Subjects box everything else that follows is irrelevant. So where is this going? Are we going to get a bunch of random pictures of rounded cards and square cards, pretend we know what packaging they originally came from, and then draw likely arbitrary conclusions about what differentiates them when any differentiating factors may be completely random or specific to the impact of the environment on the cards from the decades that followed their manufacturing, and then call this research?

Ted and Shaun have captured a lot of great background info on late 40's bread cards from their own personal experience and verifiable data coming from contemporaneous publications. Ted took the right approach when he dropped out of what is happening now when the process stopped becoming valid and reliable versus anything resembling academic research standards. In all likelihood the vast majority of distinctly rounded corner cards that have specific color/toning/contrast on the front and back are period to the late 40's. Yes, someone can try to imitate at least the front of these cards through cutting a square cornered card in a similar fashion and no third party grading service is going to get it right all of the time. It is what it is.