Is The Vertical Line On This $100 A Misprint, Or Just Something That Happened After The Printing Process?

[CorinneEllis]

Here is a link to a picture of the $100 bill:
ttps://prnt.sc/WzUL0z6SEtQV

[Buenchico]

Welcome to The Answerbank.

Your link seems to have dropped the 'h' that should be at the start of it, so here it is in clickable form:
https://prnt.sc/WzUL0z6SEtQV

The Answerbank is a UK-based website, so I doubt very much that we've got any experts on US banknotes here.

However it looks to me as if the note has been over-stamped with both the vertical line and the number (seen sideways on, on Franklin's collar) at some stage in its life.

My guess is that such an occurrence is more likely to have happened in, say, a bank or an office accounts department somewhere (possibly as part of a note counting process), than it is to have happened at the printing stage.

[Canary42]

///However it looks to me as if the note has been over-stamped with both the vertical line and the number (seen sideways on, on Franklin's collar) at some stage in its life. ///

Yes, it does look like it. I'm not sure how to confirm it, but perhaps you could gently and very carefully try to erase a tiny piece (say with an eraser (I nearly said rubber, but of course that means something else Stateside!) or a damp cloth - if it starts to come off then definitely after printing (unless other stuff comes off with the same treatment) - if it remains then we're really no further forward.

Best I can suggest, you really need an expert on US banknotes.

[Buenchico]

Further to the above, I would expect any printing error to appear in the same colour ink as is found elsewhere on the note.

The engraving of Franklin's portrait is consistently grey (or 'gray', as our American cousins would write) throughout but the mystery line and number seem to have a blue/purple tint to them.