A printer assembly includes an ink supply mechanism that incorporates a printhead. A platen is operatively connected to the ink supply mechanism. A capping mechanism is mounted on the platen and has an elongate capping arm for moving towards the printhead into a capped position and away from the printhead into an uncapped position. A biasing arrangement biases the capping arm into the uncapped position. A moving arrangement moves the capping arm into the capped position.