An image forming apparatus includes a color image forming portion for forming a color toner image on an image bearing member and a transparent image forming portion for forming a transparent toner image on the image bearing member. The color and transparent image forming portions form test color and test transparent toner images on the image bearing member. A detecting portion detects a density of each of the test color and test transparent toner images and a control portion controls an image forming condition for an image to be formed on a recording material, on the basis of a result of the detection. The test transparent and test color toner images are formed on the image bearing member between operations for forming the images on the recording material. A frequency of formations of the test transparent toner images is lower than that of the formations of the test color toner images.