An inkjet printhead assembly includes a repositionable shutter mechanism adapted to block a slot through which drops of ink ejected from the array of nozzles pass before they impinge on the print medium. The shutter mechanism includes a repositionable shutter blade extending in a cross-track direction having a pivot axis passing through first and second tabs affixed to its ends. A first slide mechanism component is pivotably attached to an end of an actuator rod, and a second slide mechanism component is rigidly attached to the repositionable shutter blade. An actuator is configured to translate the actuator rod, thereby pivoting the repositionable shutter blade about the pivot axis between a first pivot position where the shutter blade blocks the slot and a second pivot position where the shutter blade is moved away from the slot so that drops of ink can pass through the slot.