Ink-jet image forming method and ink-jet image forming device

An ink-jet image forming method forms an image by forming dots using a fast-drying ink and a slow-drying ink, in which, when forming an image, an ambient temperature of an area where the image is formed is detected, and dot density of a predetermined area of the image is recognized based on image data. A process used to form dots is selected based on the detected ambient temperature and the recognized dot density. Under the condition where the inks are easily dried, the slow-drying ink is used to form dots, and under the condition where it is difficult to dry the inks, the slow-drying ink is used suitably with the fast-drying ink to form dots. As a result, the inks can be dried efficiently while suppressing deterioration of image quality.