The scientific study of Attic vase paintings was advanced especially by John D. Beazley. Beazley began to study the vases from about 1910 onwards, inspired by the methodology that the art historian Giovanni Morelli had developed for the study of paintings. He assumed that each painter produced individual works that can always be unmistakably ascribed. To do so, particular details, such as faces, fingers, arms, legs, knees, garment folds and so on, were compared. Beazley examined 65,000 vases and fragments (of which 20,000 were black-figure). In the course of six decades of study, he was able to ascribe 17,000 of them to individual artists. Where their names remained unknown, he developed a system of conventional names. Beazley also united and combined individual painters into groups, workshops, schools and styles. No other archaeologist has ever had as formative an influence on a whole subdiscipline as had Beazley on the study of Greek vase painting. A large proportion of his analysis is still considered valid today. Beazley first published his conclusions on red-figure vase painting in 1925 and 1942. His initial studies only considered material from before the 4th century BC. For a new edition of his work published in 1963, he also incorporated that later period, making use of the work of other scholars, such as Karl Schefold, who had especially studied the Kerch Style vases. Famous scholars who continued the study of Attic red-figure after Beazley include John Boardman, Erika Simon and Dietrich von Bothmer.