An image forming apparatus for outputting a printed product includes a fusing unit, an image forming control unit to receive print data and print attribution information for printing the printed product; and a print engine including a fusing controller to control a fusing temperature of the fusing unit. The print engine outputs the printed product using a fusing temperature designated by the print attribution information. The fusing controller determines a target fusing temperature for the fusing unit by comparing a first fusing temperature and a second fusing temperature. The first fusing temperature is used for a most recently conducted fusing process. The second fusing temperature is designated by the print attribution information. The fusing controller determines the target fusing temperature to the first fusing temperature or the second fusing temperature depending on the number of colors required for printing the printed product.