Cyanotype is a type of photographic printing process that results in a cyan-blue print. This process was extremely popular in the engineering world up into the twentieth century. Cyanotype printing is known for being inexpensive and simple, allowing for large-scale productions of work known as blueprints. The two main chemicals used in the process: potassium ferricyanide and ammonium iron citrate.
Sir John Herschel was an English scientist and astronomer who is given credit for first discovering this printing technique in the early 1840s. Although he developed this method, he primarily used it for the reproduction of notes and diagrams, such as blueprints. Anna Atkins is the individual who brought this technique into the world of photography.
In fact, she also produced a series of Cyanotype books. In these limited-edition books, Atkins documented plant life, using a variety of subjects. She placed the specimens on coated paper, which created a silhouette effect. Through her use of this photograph method, Atkins is known as a pioneer for female photographers.
In the usual Cyanotype procedure, equal amounts of ferric ammonium citrate and potassium ferricyanide are mixed together. This solution is mildly photosensitive. It is applied to a cloth, paper, or other receptive surface and given time to dry in an area that is dark. Cyanotypes may be printed on any surface that is capable of soaking up this iron solution, such as watercolor paper, wool and cotton.
Exposing this print to UV light, through contact negative, is what allows for production of positive images. The UV light works by reducing iron from level III down to level II. Then, iron II and ferricyanide create a reaction. The end result is what is called Prussian blue. UV exposure, including that of sunlight, lowers the iron level. This results in a change of paper color to a blue-gray color. The total color change is based on the UV light amount a print is exposed to.
Once exposure is done, the picture must be developed by rinsing the unreacted solution with running water. The blue color is expected to darken up as it becomes dry. Usually, the desired result of a Cyanotype is a blue color. Still, many different effects may be applied with this kind of printing, such as: reducing, intensifying and toning.
Reducing refers to the process of lowering the intensity of the final blue. Dektol, borax, TSP, Clorox, ammonia, carbonate and other such reagents may be used in this process. When applying reducers, it is important to pull the print from the weak solution and place it into a water bath to stop the bleaching process. Intensifying strengthens the blue color. To expedite oxidation of these prints, employ reagents such as lemon juice, vinegar, citric acid and hydrogen peroxide. Toning involves changing color of iron in a print. The change in color will vary based on the reagent applied. Tannic acid, cat urine, oolong tea, pyrogallic acid and wine are just some of the elements that may be used for this purpose.
Cyanotype printing has been around since the 1800s. The process utilized ammonium iron III citrate and potassium ferricyanide, among other chemicals, to create blueprints. There are an assortment of variations that can be made to these prints. The first female photographer, Anna Atkins, introduced this technique in photography printing.
Sir John Herschel was an English scientist and astronomer who is given credit for first discovering this printing technique in the early 1840s. Although he developed this method, he primarily used it for the reproduction of notes and diagrams, such as blueprints. Anna Atkins is the individual who brought this technique into the world of photography.
In fact, she also produced a series of Cyanotype books. In these limited-edition books, Atkins documented plant life, using a variety of subjects. She placed the specimens on coated paper, which created a silhouette effect. Through her use of this photograph method, Atkins is known as a pioneer for female photographers.
In the usual Cyanotype procedure, equal amounts of ferric ammonium citrate and potassium ferricyanide are mixed together. This solution is mildly photosensitive. It is applied to a cloth, paper, or other receptive surface and given time to dry in an area that is dark. Cyanotypes may be printed on any surface that is capable of soaking up this iron solution, such as watercolor paper, wool and cotton.
Exposing this print to UV light, through contact negative, is what allows for production of positive images. The UV light works by reducing iron from level III down to level II. Then, iron II and ferricyanide create a reaction. The end result is what is called Prussian blue. UV exposure, including that of sunlight, lowers the iron level. This results in a change of paper color to a blue-gray color. The total color change is based on the UV light amount a print is exposed to.
Once exposure is done, the picture must be developed by rinsing the unreacted solution with running water. The blue color is expected to darken up as it becomes dry. Usually, the desired result of a Cyanotype is a blue color. Still, many different effects may be applied with this kind of printing, such as: reducing, intensifying and toning.
Reducing refers to the process of lowering the intensity of the final blue. Dektol, borax, TSP, Clorox, ammonia, carbonate and other such reagents may be used in this process. When applying reducers, it is important to pull the print from the weak solution and place it into a water bath to stop the bleaching process. Intensifying strengthens the blue color. To expedite oxidation of these prints, employ reagents such as lemon juice, vinegar, citric acid and hydrogen peroxide. Toning involves changing color of iron in a print. The change in color will vary based on the reagent applied. Tannic acid, cat urine, oolong tea, pyrogallic acid and wine are just some of the elements that may be used for this purpose.
Cyanotype printing has been around since the 1800s. The process utilized ammonium iron III citrate and potassium ferricyanide, among other chemicals, to create blueprints. There are an assortment of variations that can be made to these prints. The first female photographer, Anna Atkins, introduced this technique in photography printing.
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