1. A printing apparatus that prints an image comprising: a central processing unit (CPU) that functions as a receiving section that receives image data and print setting data from an external device in communication with the printing apparatus, the image data representing an image, and the print setting data including a plurality of different print settings of the external device; a setting section that performs setting based on designated setting content of the printing apparatus, the setting content being designated to contribute to a reduction in environmental load; a judging section that judges whether or not printing according to the setting content that is set by the setting section and according to the plurality of different print settings of the external device corresponds to environment-friendly printing which satisfies a predetermined environmental performance; an attaching section that attaches an attachment image to the image indicating that printing was performed using environment-friendly printing, when the printing according to the received plurality of different print settings of the external device and according to the setting content that is set corresponds to environment-friendly printing; and a printing section that prints the image to which the attachment image is attached, according to the received plurality of different print settings of the external device and according to the setting content that is set by the setting section, wherein the setting content includes a plurality of different print settings of the printing apparatus; and the judging section judges whether or not the printing according to the setting content that is set corresponds to the environment-friendly printing, based on a contribution of each of the plurality of different print settings of the printing apparatus and each of the received plurality of different print settings of the external device to an overall environmental performance, and the setting section determines whether or not any of the plurality of different print settings of the printing apparatus overlap any of the plurality of different print settings of the external device, and the judging section excludes the overlapped one or more of the plurality of different print settings of the external device or the printing apparatus from the judging.