The type of paper that you use in your cash register or credit card machines is called thermal paper. Thermal paper is a kind of paper that is heat sensitive. It is coated on the outside with special chemicals that make it react to heat. This printing process is called thermal printing. You can save money as you do not need printer inks or changing the ribbons. You can determine thermal paper with a regular paper by scratching the surface with the fingernail, if it changes to black, it is thermal paper.
Your cash register and credit card rolls have certified paper grade by the printer manufacturer. A lot of people might not know this that your credit card and cash registers work efficiently for a certified paper grade. The printers have proper printing mechanisms that only work smoothly for the specific paper grade. Without those paper grades, the print system is prone to jamming and wasting your time. Fortunately, hundreds and thousands of hours are put in testing the quality of the paper grade. You also have the responsibility to use the approved paper if you have the approved paper list.