Currency strap

[2] In the United States, the American Bankers Association (ABA) has a standard for both value and color.

That is, they employed 55 currency counters whose job it was to count as well as, by touch and feel, authenticate bills.

To help the Currency Counting staff keep up, the Bank began strap-sorting the $1 to $20 notes.

Straps were visually inspected and weighed against a counterweight equal to the paper mass of 100 genuine U.S. notes.

Currency straps have even helped catch the culprits in bank robberies, like the Dunbar Armored Robbery in 1997, after one of the culprits decided to pay a real estate broker with a still-strapped bundle of notes.

A stack of 100 United States $2 bills , secured with a green banknote strap indicating the denomination and total amount in the stack.
Two stacks of 100 20 euro notes and one stack of 100 50 euro notes delivered to a bureau de change by G4S .
A simple homemade currency strap holding 80 $1 bills , made from a loop of paper secured with sellotape
A stack of $100 Federal Reserve Notes in $10,000 straps. Note the ABA compliant mustard color.