Prepainted steel sheet is coated with organic layer, which provides higher anti-corrosion property and a longer lifespan than that of galvanized steel sheets.The base metals for prepainted steel sheet consist of cold rolled, HDG electro-galvanized and Hop-dip zinc-alu-mag base metal. The finish coats of prepainted steel sheets can be classified into groups as follows: polyester, silicon modified polyesters, polyvinylidene fluoride, high-durability polyester, etc.