1. An image forming apparatus which uses at least two types of liquid developer to form a plurality of images that are superimposed on a sheet to form an image, comprising: a transfer mechanism configured to transfer the image to the sheet; an image forming mechanism configured to make the transfer mechanism carry the image; and a rubbing mechanism configured to rub the image on the sheet; wherein: the at least two types of liquid developer have different fixing properties from each other; the transfer mechanism includes a carrying surface configured to carry the image from the image forming mechanism; and one of the plurality of images between the carrying surface and another of the plurality of images has higher fixing properties than the liquid developer used for forming the other image among the plurality of images.