How is Round Perforated Made? Round perforated is a sheet or coil of material made from metal or plastic (see PlastiPerf) that contains holes punched by a die. The shape of the hole is determined by the shape of the die. For perforated with a round hole pattern, the die is circular. The die's diameter can vary from approximately twice the thickness of the material being punched to over two inches. Common, in-stock sheet sizes for perforated round hole products include: · 48 x 120 inches · 48 x 144 inches · 48 x 96 inches · 36 x 120 inches