A cyanotype picture is a blue-and-white image made using a special light-sensitive coating and sunlight. When objects or a photo negative are placed on the coated paper and exposed to light, the uncovered areas turn a deep Prussian blue, while the covered parts stay white or pale. The result often looks soft, dreamy, and slightly vintage—kind of like a blueprint or a shadow captured in blue.  The word 'blue print' originates from around 1882 when the process was used to make architectural drawings.  Before this each drawing had to be painstakingly copied by hand or via expensive photolithographic processes.