Reverse Shadow. A light reflective area on tin and high tin alloys, including pewter and some white metal struck pieces caused by surface displacement during striking. This is an unusual property of coining metallurgy where the surface will not tone but becomes lighter and reflective than adjacent areas. Tin compositions do not in certain areas where the flow marks will continue to be bright while the remainder of the surface will darken by toning. Usually lettering (because of the stress in forming these) will exhibit this bright reverse shadow effect. The surface tones in time, the stress area remains bright, forever! Evidence of this “negative shadow” is a diagnostic that the composition is high in tin content.