... between the plates when they are piled up.And the surface is smoothly without freckles4) ... Inclusion, Scratches, Stain, Oxide Discoloration, Breaks, Corrosion, Roll Marks, Dirt Streaks and other defect which will interfere ... are aluminum sheet, aluminum coil, corrugated aluminum roofing sheet , embossed aluminum sheet/coil ,color coated aluminum coil/sheet ,aluminum foil, aluminum strip, aluminum wire ...