End graft/heel cap, Ebony, 2" x 7" x .125"
An end or butt graft will tie in the binding on the top and back of the guitar where the sides meet and should allow enough extra material for a heel cap. Besides being decorative, an end graft gives some wiggle room at the butt end of the guitar if you can't get the joinery on your sides just right. End grafts are typically, but not always, the same material as the binding. They can be rectangular, wedged or they can just be an extension of the binding scheme.