The process of creating a blueprint is something that was first seen in the mid nineteenth century and was the invention of an astronomer. There were a significant number of chemicals required for the process that would have been used by a Long Island blueprinting service and these chemicals included things like potassium hexacyanoferrate and iron ammonium citrate. These various chemicals were used by the inventor's cyanotype process which coated a piece of paper with chemicals which would then react when placed under ultraviolet light. Interestingly, blueprints start out as a simple black ink sketch on translucent paper.