So how many varieties or errors or even die clash are out there that have only one or two examples? Why can't it not be completely plausible if there's a variety or error found 30 years ago and not another one found sense couldn't there be one not found for 30 years? I mean I've seen a few coins in my hunt that have some sort of doubling but can't be caused by machine or mechanical.
Take ejection doubling for example no matter how you look at it there's going to be some sort of precision there even if there's a vibration jolt or slip and even pinch. There's going to be some kind of pattern Left behind indicating a machine with precision it may be not functioning correctly but even a broken machine will function with precision. Just like diagnosing engine problems if it's misfiring it still has a distinct pattern to it or if there's a vacuum leak and it throttles up and down there's a pattern to it. Like a
Dryer Coin there are very distinct characteristics of any coin that goes through the lint trap of a dryer and while most dryers are built similar they have their variations but you can still tell by those precise characteristics that it went through a dryer depending at what point it gets trapped at.
The reason why I say this is because I have shared some coins that automatically get The
Machine Doubling comment. When the numbers, letters or whatever is in question has sharp lines and corners but has somewhat bubbly doubling that is two to maybe even three times thicker than the original lettering or numbers and is also outside the capabilities of a machine. And dye deterioration does not explain it because
Die Deterioration is a continuous state that flows together and blends inn. Kind of like a bike chain and sprocket at first everything's nice and tight and clean but as you ride it the sprocket points thin out and the chain stretches and everything becomes sloppy but yet smooth until it completely fails. But you wouldn't notice any alteration to the chain or sprocket if you checked it every 5 minutes because everything is smooth and meshing well together.
But the one thing that would be very apparent after deeper analysis is that the sprocket points no longer have sharp lines and corners. But if you videotaped the entire life of the sprocket and chain you would be able to see why sharp lines and corners can't be categorized with deterioration.
So my assumption is that if there hasn't already been a discovery and the characteristics of the coin can't be explained it's written off as
Machine Doubling.
Maybe I'm missing something