An image-forming system includes a transmission device and an image-forming device. The transmission device includes a transmitting unit that transmits image data, command data instructing to form an image corresponding to the image data on a recording medium having a storing part and to write embedded data to the storing part, and first selection data indicating whether or not the image should be formed when the embedded data cannot be written in the storing part. The image-forming device includes an image-forming unit and a controlling unit. The controlling unit controls, when the image-forming unit cannot write the embedded data in the storing unit, the image-forming unit to form the image if the first selection data indicates that the image should be formed, and to fail to form the image if the first selection data indicates that the image should not be formed.