A scalable expandable spray ink printer machine for use with paper roll stock is disclosed. A series of three or four print heads are place serially in proximity to paper stock. The configuration of the cylindrical print head allows the heads to be expanded for printing on wider paper stock. The print heads include a combination of fixed, turning and sliding components to align or block ink flow from the print ink reservoir. The printer is in fixed position perpendicular to the travel direction and rotates internally on an axis parallel to the paper or media to be printed. The print head is sectional and lengthwise expandable in fixed unit lengths. The printing machine is ideally suited for advertising or other elongated print media. Due to the use of standard paper, roll stock and speed of the printing, signs can be printed on demand and displayed in real-time.