Cyanotypes or Blue Prints were invented by John Herschel in 1842. In the days before photography, John was looking for a way to share his notes and diagrams with his fellow scientists. Two chemicals are mixed together and painted on to paper. As long as the paper stays in the dark, nothing happens but when sunlight or UV light shines on the paper a chemical reaction occurs and the two soluble chemicals react to form Prussian blue, an insoluble blue dye. The soluble chemicals are washed away leaving a blue and white image. The process was used extensively for copying plans for building and ships until the 1940s.
Today the process is still used by artists. In our cyanotype workshop, children had the opportunity to make photograms by placing objects directly on the paper and to copy their own drawings.
My cyanotype workshop was part of the Abu Dhabi Science Festival 2019, over 3000 cyanotypes were made by children with their schools or families in ten days.