In either type of offset press (Stone or plate) the paper shouldn't come in contact with the plate. Those very clear offsets are usually from a misfeed causing the offset blanket to print to the impression roller which is a nice smooth steel. If it's a minor misfeed and the press isn't stopped then the next sheet gets an impression from both the blanket and the impression cylinder.
The paper does sometimes contact the plate. But it's a bigger problem, and the result looks awful. And nearly always ends up in the round file. Basically the paper or what's left of that sheet gets inked, and prints a nearly solid layer of that color to the next sheet. If there is one. The sort of jam usually involves the paper tearing or peeling so some winds around the blanket.
I still haven't quite figured out if they were done with stones or plates. I'm almost positive the backs were done with stones. But I'm less certain of the fronts.
Steve B
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