An image forming apparatus including an image forming unit that ejects droplets on a image forming apparatus, and forms an image on a surface of the printing medium; a pre-processing unit that applies a pre-processing liquid to the surface of the printing medium before forming the image by the image forming unit; and a post-processing unit that applies a post-processing liquid, that is different from the pre-processing liquid, to the surface of the printing medium after the forming of the image by the image forming unit, wherein the pre-processing unit applies an amount of the pre-processing liquid which is determined based on resolution of the formed image on the printing medium, the post-processing unit applies on amount of the post-processing liquid which is determined based on the resolution of the formed image on the printing medium.