Posted By:
scott brockelmanBob,
I don't think the blank backs are from posters cut up, there are way too many of them circulating. Imagine another series where nearly 50% of the known cards were cut from posters, I don't think you would find 1% of them from any type of advertising.
Also I can't think they are printers scrap as most are fully finished cards, and not partial press runs, further if they were printers scrap they should have the same back as the framed, the frame most certainly wasn't added later.
Scott