Hi Imho, it kind of looks like plating blisters or form of bi-level die cracks.? Though i could be wrong. I’m sure the experts can better explain. What is the weight? http://www.error-ref.com/?s=Plating+blisters+ http://www.error-ref.com/bi-level_die_cracks_/
Yes and no... Plating blisters called linear plating blisters but it has absolutely nothing to do with bi-level die cracks..