Test colors are halftone dot printed at the rate of 10% halftone dot area by process inks black, cyan, magenta and yellow ink. Reproduced colors are measured by the weighted-ordinate colorimetric method and the direct colorimetric method. The weighted colorimetric method compare favorably with the direct colorimetric method, because the former has good regular changes of tristimulus values, chromacity coordinates, excitation purities, value functions and has smaller errors of dominant and complementary wavelengths than the latter