PMS Colors vs Process Colors
Process and PMS (Spot) are two different systems for generating colors.
Process colors are created by applying separate layers of 4 colors - Cyan, Magenta, Yellow and Black (CMYK) - in various concentrations on the paper. By mixing these 4 colors, just about any imaginable color can be created. CMYK 4-Color Process is commonly used for printed matter that contains photographs.
PMS colors, also known as Spot colors or Pantone Matching System colors, are specific color formulas that will reproduce accurately in print. Instead of simulating colors by combining multiple colors as in CMYK 4-Color Process, PMS colors are pre-mixed from existing color formulas and assigned a standardized number. Using a PMS color provides assurance of having consistent color regardless of when or where the printed piece is produced. However, because PMS ink colors are specific formulas, there is usually an upcharge.
PMS colors are commonly used for a logo or text that requires a consistent appearance, such as on business stationery. It is very important that you don't use PMS Spot colors in your artwork design if you are printing in CMYK 4-color Process. When designing for CMYK 4-color Process, it is always a good idea to refer to the Pantone Process Book and then use the Process color that is closest to the desired PMS Spot color. Otherwise when your PMS Spot color converts to a Process color, it could yield a result you weren’t expecting.