So far we've seen channels created with lassos, the pen tool, and shape layers. Though these are the most common methods, some tricky shapes require an entirely different strategy: channels. This video shows how to use alpha channels to create complex selections. I'll be the first to admit that channels are confusing, and don't immediately appeal to illustrators. Hopefully this short video will change your opinion!
If you find this topic interesting, make sure to check out Edge Control to learn more advanced techniques!