A method and system for printing bi-directionally with a thermal print head movable back and forth along a print path adjacent a ribbon to transfer ink therefrom onto a substrate. The ribbon being drawn from an unwind reel and adjacent the print path, and the ribbon being clamped to maintain tension on the ribbon at least when the print head moves in the same direction as ribbon is drawn along the print path. A rotary drive member is rotatable in a first direction to actuate a brake member that clamps the ribbon against a fixed ribbon guide, and the rotary drive member is rotatable in a second opposing direction to rotate the rewind reel to draw ribbon from the unwind reel.