Adobe Photoshop CS4 Studio Techniques

Channels

In older versions of Photoshop, you used channels to isolate complex images from their backgrounds. These days, you’ll mainly use channels with simpler images, especially when working with an illustration instead of a photographic image. Often, you can convert images into spot colors so that each color in the image prints with a different color of ink (instead of printing with standard CMYK inks). Channels are the subject of one of the bonus videos on the book’s website (www.danablan.com/photoshop), but for the moment let’s look at how to use the Channels panel to isolate each color within an image. This might seem cumbersome at first, but read on and you’ll see the value of this approach.

Let’s say you have a logo or graphic that you’d ...