An image forming apparatus includes a first developing device for developing an electrostatic image with a first developer including a non-transparent toner and a carrier; a second developing device for developing an electrostatic image with a second developer including transparent toner and carrier; a first supplying device for supplying a first supply developer including non-transparent toner and a carrier to the first developing device; a first supplying device for supplying a second supply developer including transparent toner and a carrier to the second developing device; a control device for superimposing a toner image of the transparent toner on the non-transparent toner image so as to reduce a height difference in toner layer or layers of the toner image provided by the non-transparent toner, wherein a carrier weight ratio in the first supply developer and a carrier weight ratio in the second supply developer are substantially equal to each other.