Adobe Photoshop Unmasked: The Art and Science of Selections, Layers, and Paths

Photoshop features three types of channels: color, alpha, and spot color channels. Color channels tell us a lot about the qualities of our images; alpha channels allow us to save and recall selections and make accurate masks, as well as give us more creative options; and spot color channels expand our range of printing options. It's by using channels that we can understand the images we are editing. As you can see from the examples in this chapter, channels are commonly used in conjunction with other selection methods like paths and layer masks. As we'll see in the next chapter, they are also closely related to, but distinctly different from, layers.