Zinc coated steel substrate for PPGI is typically produced on a continuous galvanizing line (CGL). The CGL may include a painting section after the hot dip galvanising section, or more commonly the metallic coated substrate in coil form is processed on a separate continuous paint line (CPL). High quality PPGI prepainted galvanized steel coil produced in China is no problem. Metallic coated steel is cleaned, pre-treated, applied with various layers of organic coatings which can be paints, vinyl dispersions, or laminates. The continuous process used to apply these coatings is often referred to as Coil Coating.

The coil coating process may be used for other substrates such as aluminium, or aluminium, stainless steel or alloy coated steel other than "pure" zinc coated steel. However, only "pure" zinc coated steel is typically referred to as PPGI. For example, PPGL may be used for pre-painted 55%Al/Zn alloy-coated steel (pre-painted GALVALUME(r) steel*)