A post-processing liquid application device includes an ejecting head that ejects a post-processing liquid in a specific ejection pattern on a recording medium after ink has been attached thereto to form a character and/or an image based on image information, and a control unit that selects the specific ejection pattern based on a coverage rate calculated from the image information. When the coverage rate is low, the control unit selects a first ejection pattern for ejecting the post-processing liquid on a printed portion of a print region of the recording medium or ejecting the post-processing liquid on the printed portion and a surrounding portion thereof. When the coverage rate is high, the control unit selects a second ejection pattern for ejecting the post-processing liquid over the entire surface of the print region of the recording medium.