I had some difficulties changing the older dollar bills at cuevas, the ones that dont have the blue thick iridescent line, In the middle across the bill. Because Argie Customers don't want to buy them.
Also if the bill has any marking be it a handwritten message, a heart, or a tinsy little seal can sometimes be rejected. Last month I had a $100 dollar bill that had stamped three digits in black ink (234) like in an ascending ladder . I believed it was part of the bill numbering. It was turned down by 2 buyers.
Next time I will receive only new 100 dollar bills with the blue iridescent line on the center of the bill.....!