Abstract: A medium for printing, such as a thermal receipt roll for an ATM. The medium has two sides, each side having a plurality of marks positioned to trigger an automatic operation, such as printing, movement, or cutting of the medium when identified by a detector. Preferably, the marks are adapted for optical sensing by a detector located along one side or the other of the roll, and are positioned at regular intervals along the side edges. This allows the roll to be used in business machines having different detector configurations.