The ISO 8504-1:2019 "Preparative method of steel backing before use for Coating and related products - Part 1: General principles" standard outlines general principles on how to select and implement steel surface preparation prior to coating paints and related products. The standard highlights the effect of the surface state of steel on coating performance, including factors such as rusting, contaminants and surface profile. The ISO 8504 series provides guidance on the surface prepative method of steel substrates, but does not include requirements for specific coating systems. Users should choose the appropriate surface preparation method based on the environmental conditions to which the steel will be exposed and the requirements of the coating system. This document is used in conjunction with the Miscellaneous parts of the ISO 8504 series, such as sand blasting cleaning and Miscellaneous surface preparation methods, to ensure that the steel surface meets the required level of cleanliness and preparation.