It's struck-through grease. These dies get a little hot from all the pounding, just like an engine. You give Valvoline to the engine and grease to the dies.
That's a really good "greasy". All rim lettering wiped out. Just wait. Some jabronie will refer to it as an "atheist cent".
Hey, that's one of those "atheist coins"!!! (& I'm OK with either the Italian translation or the wrestling meaning!)
