How do color matching systems, such as Pantone or Trumatch, help a printer specify spot color inks?

The color you select from the PMS swatch books tells us what color to print. A printer finds the exact mixing specifications for your chosen color beneath each swatch of color on the chart. Within printing, lighting, and human eye tolerances, the PMS color you specified from your swatch book should look the same as the one we print for you.

To prevent selection of the 'wrong' color, make sure to select your color from a new swatchbook. Swatchbooks fade with time and use, and should be replaced yearly.

Pantone's process color matching system has recently been improved to order colors by the amount of black in each process color build. This is somewhat similar to the Trumatch process color matching system which divides the spectrum into 50 hue families with 40 tints and shades of each hue, plus 4-color grays.