There are times when projects are going to be designed for multiple print channels, like a magazine ad (CMYK) and a direct mail piece(Pantone solid color). This presents some very real problems for the designer and the printer, as some colors just will not match. The Pantone solid color might be clean and bright and the CMYK version might be dull and dirty. The example on the left shows you exactly what happens when trying to reproduce 185 red in both processes. With the color bridge in hand, you can select colors which reproduce equally well in both processes. At the very least, you will know what they will look like.(No surprises). More information on the Pantone color bridge here.