the increased popularity of "aizuri-e" is directly linked to the 1829 importation of the first synthetic colouring agent to japan. known in the west as prussian blue, berlin blue, or "bero" (ベロ) as it came to be known, effectively challenged natural indigo as an "ukiyo-e" mainstay due to its lower price and decreased susceptibility to fading from light exposure. "aizuri" has been described by one critic as having "revolutionized landscape prints."