Note: The gold-phased test module is to be polished, and in order to make clear the boundary between the plating and the matrix, the plating and plating, the test on the module should be weakened before observation. If the metal colour between the plating and the matrix is close, the plating of the other colours between the two is to be applied as a line of line of line of line... for example, copper is to be plating between the silver white matrix and the plating.