4 Color Process is a printing process using 4 main inks, Cyan, Magenta, Yellow, and Black or CMYK for short. A color image is "separated" into 4 color separations (see sample below) then each individual separation is printed. When all 4 separations are printed they combine into a 4 color image or a "full Color" image. Due to Ink pigment deficiencies and the process it takes to generate separations, 4 Color printing sometimes cannot achieve certain colors that are outside the gamut or range of those inks. To achieve these certain colors sometimes a SPOT COLOR is used in combination with 4 color printing especially when using metallics to achieve a certain color.