Flow blue china originated in England around the 1820s-1830s as potters tried to replicate Chinese porcelain, with the characteristic blurry blue design occurring when chemicals were added to the kiln to intentionally or accidentally cause the cobalt blue glaze to "flow" and blur into the white background. It was a very popular export, especially in America, and its designs evolved over time from early Oriental motifs to include later floral, landscape, and even Art Nouveau patterns.