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, an English astronomer and scientist, is credited with discovering this technique in 1842. Although Herschel originally developed the process, he used it mostly as a means for reproducing diagrams and notes, including blueprints. Anna Atkins is the artist who brought it into the photographic world.
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 the piece to ultraviolet light, through a contact negative, produces positive images. The UV light lowers iron III to iron II, which is followed by a reaction between the iron II and ferricyanide. The result is called Prussian blue. Exposure to sunlight, or other ultraviolet light, reduces the iron level and turns the paper a steel-gray, blue-like color. The amount of change in color is dependent on the amount of ultraviolet light.
After the step of exposure is complete, picture development involves yellow unreacted solution being rinsed using running water. The blue color will darken as it dries. With Cyanotypes, blue is typically the desired color. However, an assortment of effects can be achieved through with this type of printing. These are categorized as toning, intensifying, reducing.
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 is a process that was first discovered in the 1840s. This process involves potassium ferricyanide and ammonium iron III citrate. The effect of this printing process is blueprints, but there are many variations that can be done to change the appearance of a print. Anna Atkins, known as the first female photographer, was first to introduce this process in photography.
Sir John Herschel, an English astronomer and scientist, is credited with discovering this technique in 1842. Although Herschel originally developed the process, he used it mostly as a means for reproducing diagrams and notes, including blueprints. Anna Atkins is the artist who brought it into the photographic world.
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 the piece to ultraviolet light, through a contact negative, produces positive images. The UV light lowers iron III to iron II, which is followed by a reaction between the iron II and ferricyanide. The result is called Prussian blue. Exposure to sunlight, or other ultraviolet light, reduces the iron level and turns the paper a steel-gray, blue-like color. The amount of change in color is dependent on the amount of ultraviolet light.
After the step of exposure is complete, picture development involves yellow unreacted solution being rinsed using running water. The blue color will darken as it dries. With Cyanotypes, blue is typically the desired color. However, an assortment of effects can be achieved through with this type of printing. These are categorized as toning, intensifying, reducing.
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 is a process that was first discovered in the 1840s. This process involves potassium ferricyanide and ammonium iron III citrate. The effect of this printing process is blueprints, but there are many variations that can be done to change the appearance of a print. Anna Atkins, known as the first female photographer, was first to introduce this process in photography.
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