Totally agree with the above two comments. If you magnify US currency enough you can find inking flaws on almost every note. It probably doesn’t look nearly as bad if not magnified. Maybe @bryantallard can post a full size photo.
They do the same with coins. Smack up against your nose what's not going to look strange? Then they think they found the discovery of the ages.
In the printing business, this is called feathering. Feathering in intaglio printing is usually caused by ink that is too thin or paper that has not been sized properly so the ink seeps into the fibers of the paper instead of laying on top of it.
Too much solvent, or thinner was my first thought but went with over inking because it is a much more common term for this error. In the case of US Currency, what would they size it with? or any intaglio print for that matter. I'm not trying to get in the money printing business, just wonder what affects it adds to the paper other than fiber seal. Is embossing the only thing that gets currency a PQ grade?
This isn't my note, I was asking for someone I was asking for somebody in a Facebook group. I am a moderator, but I do not know everything. I did not think it was the find of a lifetime which is why I said inking issue instead of thinking error. It gave me an opportunity to learn something and to be of help to someone else
