These are low cost metallic substrates to replace expensive solid metal panels when the primary interest is in appearance. Each card has a 1/4 inch (6.4 mm) diameter hole punched in one end. The test surface has a high metallic luster. In addition to lower cost, a major advantage over regular metal panels is that they are much lighter in weight and therefore more conveniently stored. They are available with one side primed with a clear organic primer for improved adhesion. They are also available unprimed.