A flat bed screen printing machine wherein the material to be printed is movable in stepwise fashion with or relative to an assembly including a flat bed at one side and a screen at the opposite side of the path for the material. The material moves with the assembly during application of paste and moves slowly relative to the assembly while the latter moves rearwardly to its starting position. The slow movement of the material serves to move its passer marks to optimum positions with reference to a detector. One or more stationary squeegees are adjacent the screen. The screen can move relative to the squeegee(s).