A screen printing apparatus prints on a substrate with successive strokes, which may be of different lengths. An electrically programmable controller controls the operation of a servo motor for causing relative movement between the squeegee and the print head during a printing stroke. A programming apparatus is provided at the print head for programming the programmable controller to establish the starting point, and the end points of the printing stroke as well as the velocity of movement of the print stroke travel between the starting and ending points. The programming apparatus preferably includes a data entry device and a display for allowing the adjusting of the print stroke to absolute units of speed, e.g., inches per minute, to allow the printing inks to be sheared and spread in an optimal manner.