A major breakthrough for Miro's graphic work arrived through an introduction, by renowned master printmaker Robert Dutrou, to carborundum (silicon carbide engraving) in 1967. The Carborundum printmaking process, pioneered by Henri Goetz, is an engraving technique requiring the use of an abrasive ground (carborundum) added to the etching plate to create a granulated or textured surface. Joan Miro found that by combining this new technique with other etching methods, especially aquatint (a painterly technique of engraving a resin ground on an etching plate rather than the plate itself), Miro could invent images to rival any painting, thereby ennobling the art of printmaking. The etchings and aquatints with carborundum, created from 1967 through 1969, set an incomparable standard for quality and indicated to the artist the incredible possibilities inherent to the carborundum technique, which Joan Miro would continue to explore throughout the balance of his career. The importance of this series of carborundum aquatints conceived from 1967 through 1969 was recognized by the Museum of Modern Art, New York in 1970 with a special exhibition devoted to them titled Joan Miro: Fifty Recent Prints.