1. A printing apparatus comprising: a transport unit configured to transport a transparent medium in a transport direction; a first nozzle array having a plurality of nozzles arranged in the transport direction, the plurality of nozzles being configured to discharge ink for forming a color image to form a color dot on the medium; a second nozzle array having a plurality of nozzles arranged in the transport direction, the plurality of nozzles being configured to discharge ink for forming a background image to form a background dot on the medium; and a carriage configured to cause the first nozzle array and the second nozzle array to move along a moving direction intersecting the transport direction, wherein the color image and the background image are formed on the medium by repeating a dot formation operation of causing the ink to be discharged from the first nozzle array and the second nozzle array moving in the moving direction to form the color dot and the background dot on the medium and a transport operation of transporting the medium in the transport direction, wherein a pixel in which the background dot is formed directly on top of the color dot that landed on the medium and a pixel in which the color dot is formed directly on top of the background dot that landed on the medium are mixed so as to form an area where the color image and the background image overlap, wherein correction processing of increasing a density of data representing the color image is performed, and the color image is formed on the medium in accordance with the data after the correction processing, and wherein a generation rate of the color dot constituting the color image in a case where the correction processing has been performed is less than two times a generation rate in a case where the correction processing is not performed.