Means for supplying ink to a plurality of individually-spaced movable print heads is caused to be moved in a direction therewith but which ink supply means is positioned and directed in a manner perpendicular to the direction of movement of the print heads. An ink container is fixed at a distance from the print heads and a separate flexible ink supply tube, extending substantially in a vertical direction, connects the container with each individual print head. The ink supply tubes are movably swung or pivoted as the print heads are caused to be laterally moved and the swinging or pivoting movement of the supply tubes prevents interruption of the flow of ink to the print heads upon reversal of travel thereof at the ends of the printing lines.