This Standard sets out a method for determining the thickness of a paint coating or coating system applied to a rigid substrate by using a paint inspection gauge.This method is also applicable to determination of the thickness of individual coats in a multicoat system where there is a visually discernible difference between coats. The method is not applicable for soft, friable or ductile substrates that may deform under the test gauge cutting tip. The determination may be carried out in either laboratory or field.NOTE: This is a destructive test method.