Adding an extra colour to your print job can greatly enhance the overall look of your final piece. Using metallic Pantone colours is just one way of doing this, and there are hundreds of colours to chose from so you don't have to stick to the standard golds or silvers.
Pantone colours can be used in a number of different ways. Perhaps you could turn all of your text silver, or use a metallic colour on flat areas, such as logos or graphic shapes. When working with Pantone colours within an image, you have two options - you could use the Duotone feature, which mixes two spot colours applied to an image or, as shown in the following tutorial, you can create an extra spot channel within a CMYK image.