Consult, woven bag printing plate making, say the spot color, which color is what ah?
In order to print out the visible light color of some CMYK four-color printing ink gamut on printed matter. CMYK four-color printing ink gamut and visible light domain compared to obvious deficiencies, and spot color ink color gamut than CMYK four-color printing ink gamut is wide, so it can show CMYK four-color ink outside of many colors;
Spot color is when printing, not by printing C, M, Y, K four-color synthesis of this color, but rather use a particular kind of ink to print the color.
Spot color inks are prepared by printing plants in advance or by ink mills. For each particular color of printed matter, there is a special color version corresponding to the printing. Use spot colors to make colors more accurate.
