A printing apparatus which prints an image on a medium, including a head which discharges ink droplets from nozzles, wherein the medium is transparent, two pieces of image data are prepared, one piece of image data is selected from the two pieces of image data to set the selected image data to one of a first image and a second image, the other piece of image data is set to the other of the first image and the second image, the image data set to the first image is subjected to a processing to be mirror image data, and the head prints the mirror image of the first image on the medium, prints a background image on the mirror image of the first image, and prints a real image of the second image on the background image.