Clipping and still jumping?

Hi

I clipped my chkns wings so they wont fly, but they jump on the 2-3 ft coop and jump on the fence and go down. How do I stop them? THey fence is 4 ft high. They jump, fly. Is there a special way to clip. I followed omlet.com or something like that way to clip. It wont work. How? Sooner or later my dogs are gonna get them when they are out.