Prepainted Galvanized Steel Coil Home Products PPGI & PPGL PPGI Coil Prepainted steel coils use hot-dip galvanized sheets, hot-dip galvalume sheets, electro-galvanized sheets, etc. as substrates. After surface pretreatment (chemical degreasing and chemical conversion treatment), one or several layers of organic coatings are coated on the surface, and then A product that is baked and solidified.