A bifurcated platen assembly is used to improve screen printing operations by providing parallel spaced apart platens instead of a single platen. The method includes steps of identifying a phase that optimizes peak characteristics, and then determining, for each of a plurality of calibrant ions, an optimal resonant ejection voltage amplitude when the ion trap is operated at the identified phase. The holographic image, for example, can be that of a video screen and the areas can be different symbols on the screen. The twist of the shaft is converted into the movement in a direction to move the pistons by first and second levers, and the pistons are moved.