Abstract: A method is disclosed for treating an aluminum alloy product in order to impart a fine grain structure and thereby improve formability and surface finish characteristics. According to this method, the product is first heated to a first temperature high enough to dissolve soluble constituent phase particles into solid solution. The product is maintained at this first temperature long enough to dissolve a major portion of the soluble constituent phase particles. Thereafter, the product is subjected to a controlled cooling process. The product is first cooled from the first temperature, at a first rate that is rapid enough to minimize the precipitation of coarse-grained constituent phase particles, to a second temperature that is below the temperature at which such coarse-grained constituent phase particles will precipitate out. Then, the product is cooled from the second temperature, at a second rate that is within a range of about 1-300 degrees F. per hour, to a third temperature that is at least 50 degrees F.