The ukiyo-e technique for creating gradient color effects is bokashi.
In bokashi, the printer applies ink unevenly across a dampened woodblock instead of coating it uniformly. The transition from darker to lighter color is then transferred to the paper, producing atmospheric bands in skies, water, clothing, and landscapes. Because the ink must be brushed onto the block by hand for each impression, no two prints are necessarily identical.
The technique became especially famous in nineteenth-century landscapes by Katsushika Hokusai and Utagawa Hiroshige. Prussian blue, a pigment increasingly used in Edo-period printing, made bokashi particularly effective for depicting distant mountains, deep water, and hazy horizons. Hiroshige also used multicolor gradations for dramatic sunrises and sunsets.
Bokashi is easy to confuse with neighboring print terms. Nishiki-e means full-color “brocade pictures” made with multiple blocks, while sumizuri-e refers to monochrome ink printing. Karazuri is a form of blind embossing that creates raised, uninked texture rather than a color gradient.