How cn you CLIP a Layer from an OLD PCB and add the Clip file to a new PCB?
You have a couple of methods:
1. You can use the Design Reuse function... if you have the option.
2. If your designs are similar enough you can run an eco from your new design to your old. It will delete some stuff, and add some stuff, depending on how close the designs are.
Those are short answers with little detail meant to fuel thought.