A very good overview on how printers encode data on printed color pages. Of note, I worked for Brinks Armored back in the 90’s, and when one of the girls in the money processing room was out on disability, they pulled me off the truck to work processing deposits for local banks, mostly fast food restaurants, with all the cash being sent to the fed. We had money counters hooked into a computer for processing the deposits. And of note, the money counter would flag counterfeit bills which we would have to document and set aside for periodic mailing to the secret service, so it wasn’t a high priority if they even investigated. Many were done with printers, but were of such bad quality you’d have to think inside job. And if they weren’t hidden in a stack, you’d spot them yourself. So it gives credence to Sam’s dismissal of the reason for this tracking being implemented for counterfeiting.