Each image was made through a process whereby Hokusai's drawing on paper was glued to a woodblock to guide the carving. The original design is therefore lost in the process. The block was then covered with ink and applied to paper to create the image (see Woodblock printing in Japan for further details). The complexity of Hokusai's images includes the wide range of colors he used, which required the use of a separate block for each color appearing in the image.