This standard describes in detail the preparatory method for testing galvanized and zinc alloy coated steel sheets for paints, varnishes and related coating products. Includes hot dip galvanizing, single-sided galvanizing, Eletroplating zinc and zinc-aluminum alloy coatings, but does not cover 55% aluminum-45% zinc alloy steel sheets. Correct zinc coating descriptions are essential for coating performance evaluation, as coating differences can significantly affect results. This method ensures substrate uniformity for reliable coating testing. All test parameters are expressed in SI units and subject to compliance with relevant safety and environment specifications.