Spot color means that the color of the image does not pass the CMYK four-color setting, but is printed by the ink that has been adjusted before printing or produced by a special ink manufacturer. Using the spot color can make color management more accurate. During spot color printing, the whiteness, gloss, and ink absorbency of the printed paper carry the greatest impact on color deviation. Therefore, when deploying spot colors, you should "sample" the paper that will be printed on the machine, and observe and Check the actual color performance so that the printing effect can be reflected more realistically.