ISO 8501-4:2006 is a hardback A5-format book in three languages (English, French and German) which specifies a series of preparation grades for steel surfaces after removal/partial removal of water-soluble contaminants, rust, previous paint coatings and foreign matter by high-pressure water jetting. The various grades are defined by written descriptions together with photographs that are representative examples within the tolerances for each grade as described in words. In addition, this part of ISO 8501 specifies both initial surface conditions and after-cleaning flash rust grades, also defined by written descriptions together with representative photographic examples.