A screen-printing apparatus for repeatedly marking an indicium at regularly spaced intervals or predefined discrete intervals on a surface or medium. The screen-printing apparatus includes a wheel mounted to a housing. A screen frame can be mounted to a housing that can interchangeably receive a screen having void(s) of a shape that corresponds to the indicia to be printed. The screen-printing apparatus also has an ink supplying unit that sprays ink over the top surface of the screen. A solenoid operably coupled to the ink supplying unit for triggering the ink supplying unit. The solenoid and the wheel are operably coupled to a control unit, the control unit can receive readings from the wheel about the distance covered by the wheel on the surface and based on the readings can trigger the solenoid at predefined intervals.