Cant find any reference to these lines being an error. Is it someone's foot print. There is some green ink bleed through to the front of the bill to the right of the bust. Also there is some extra black print on the chin of the bust. The back has some black ink that seems to be print transfer below the 'n'. There are two circles on the back. They feel raised on their circumference. There is some green ink around the 2 o'clock position of the of the circle below the 'n'. What do u think? Thanks, - Rick
It might have been pressed against a stencil of some kind, or against a ridged, inked surface. I agree with paddyman, that doesn't appear to be an error.