A computer-implemented method for gray balance calibration in an image printing system is provided. The method includes printing, using a print engine, a reference test pattern consisting essentially of black marking medium; sensing, using a sensor, the reference test pattern to obtain a reference image data, the reference image data being a function of the black marking medium; printing, using the print engine, a second test pattern comprising a combination of marking mediums of different colors, other than the color black, available on the image printing system to simulate the black marking medium; sensing, using the sensor, the second test pattern to obtain a second image data, the second image data being a function of the combination of marking mediums; and determining a difference between the reference image data and the second image data to obtain a correction offset for gray balance calibration in the image printing system.