Abstract: A coiled ink supply tube for an X, Y plotter and the like is connected between an ink reservoir and a pen mounted within a pen holder and moveable with the pen holder between a raised non-drawing position and a lowered drawing position for drawing lines or graphics on receiving surfaces. The ink supply tube defines a preformed coil having 11/4 turns or windings in the form of a helix with substantially zero spacing between turns. The ink supply tube also defines a straight inlet section coupled between the coil and the reservoir and oriented parallel to the axis of the coil, and a straight outlet section substantially coaxial with a vertical axis of the pen and lying in a plane substantially perpendicular to the axis of the coil. As the pen moves up and down between the raised non-drawing and lowered drawing positions, the diameter of the helical coil changes very little and substantially no lateral forces are imposed by the ink supply tube on the pen.