Abstract: A spark plug printing machine has two silk screens with different color inks mounted side-by-side and facing down. Spark plug insulators are rotatably mounted in a vertical orientation on a turntable. A print transfer pad located beneath the screens is rotatable from a first position, where it is horizontal and contacts the screens, to a second vertical position. In the second position the pad contacts one of the insulators and is displaced along its length to roll the insulator along the pad through more than 360.degree. so that ink from both screens is transferred to the insulator one after the other.