Abstract: A printing apparatus having an array of printheads arranged along a single printhead axis, and capable of printing images and a coating layer on the substrate during a single printing operation. The coating layer can comprise a specialized printing fluid such as a layer of substantially white ink. The apparatus can perform a pre-coat printing operation, in which the coating layer is deposited first on the substrate, and the image is then printed over the coating layer. The apparatus can also perform a post-coat printing operation, in which the image is first printed onto the substrate, and the coating layer is then deposited over the image. The printhead array includes at least one printhead for printing inks to form the images, and at least one printhead for printing a specialized fluid to form the coating layer. Depending on the printing mode, a controller allocates certain nozzles of the array for printing inks and certain nozzles for printing the specialized fluid.