Patent attributes
When forming a test chart for investigating output characteristic relating to yellow color agent, a printer outputs yellow color agent in a plurality of densities that correspond to various density levels and also outputs cyan color agent in a fixed and maximum density. Patches in gradations from cyan to green are formed by overlapping the yellow color agent and the cyan color agent. The patches are formed with respect to a surrounding area that is formed by outputting the cyan color agent in the fixed and maximum density. Accordingly, the colors of the patches are easier to distinguish than when the patches are formed from yellow only. Visual calibration can be easily performed even with the yellow color agent that has a low visual sensitivity.