Some feel that they rival the quality of traditional copper plate photogravure, while others find that the lack of differential depth in the polymer coating compromises quality.
The charts proved to be excessively expensive to photograph and reproduce, generally via engraved copper plates (photogravure), and many zones were either not completed or properly published.
Each of these works contains as many as or more than 60 prints employing techniques of photogravure, spit-bite, collage, cutting, scratching, silkscreen, offset lithography and hand-building.
