I'm still getting used to my D4. I'm cutting some 1/2" Dovetails for a large box made of paulownia. I tried using some 1/4" hardboard in front of the board to prevent tearout and it worked fine-however it sure seemed to be tough on the bit. What is the best material to use for protecting from tearout: hardboard, plywood, same wood as workpiece, other? Thanks in advance.