Tuesday , 16 July 2019

Prussian Blue: A History of Cyanotype

Cyanotype is one of the simplest and most archival photographic processes. This particular alternative photo process – or “alt photo” for short – produces a cyan blue print (hence, cyanotype) using two main chemicals: ferric ammonium citrate and potassium ferricyanide, each of which can be purchased for less than $10. Cyanotypes need only plain tap water for developing and can be printed on various papers, some fabrics, and even glass!

Inventor of the Process

In photography’s early stages, silver and dichromate were two of the three main bases for making photographic images during the nineteenth century. Iron was the third. The cyanotype process is special because it’s the first non-silver technology used to create photographic images. The English scientist and astronomer Sir John Herschel first invented cyanotype.

Herschel made experiments using photosensitive emulsions of vegetable pigments, announcing his discoveries in Royal Society of London’s Philosophical Transactions, the world’s first science journal, in 1842. That year, he published his findings in a paper called “On the Action of the Rays of the Solar Spectrum on Vegetable Colours, and on Some New Photographic Processes.”

Though the photo process was developed by John Herschel, he largely considered it a method of reproducing notes and diagrams. It wasn’t until the 1850s that various artists, like Henri Le Secq, used the cyanotype process to create prints from negatives. By 1870, a number of American companies sold personalized cyanotype paper until around the time of the Great Depression.

A Tour de Force

John Herschel is father of the cyanotype. But he also made improvements to other photographic processes. Long before cyanotype, Herschel discovered sodium thiosulfate to be a solvent of silver halides in 1819. He then informed William Henry Fox Talbot and Louis Daguerre – inventor of the daguerreotype –  that this “hyposulphite of soda” could be used as a fixer to make light-sensitive images permanent. Sir Herschel presented his groundbreaking research to the Royal Society on March 1839 and January 1840.

If the breadth of photographic discoveries and influence wasn’t enough, credit has traditionally been given to Herschel for both coining the word photography and introducing the method to the public; However, there is speculation he was preceded by Hércules Florence, who used the term photographia as early as 1832.

The word “photography” was created from the Greek roots phōtos, or “light,” and graphé, meaning “representation by means of lines” or “drawing.” Together, they translate to “drawing with light.” That said, the understanding of light and lighting are arguably the most important facets to the study of photography.

The First Female Photographer

Anna-AtkinsWhile Herschel used his process almost exclusively for notes and diagrams, it was Anna Atkins who used the cyanotype process as a method of photography. Atkins, originally named Anna Children, was heavily influenced by her father, John George Children, a respected scientist and secretary for the Royal Society. Through her father’s association with Society members William Henry Fox Talbot and Sir John Herschel, Atkins learned the cyanotype process.

She made drawings for her father’s translation of Genera of Shells in 1823, but her interest lay in the study of botany. It was later that she used the cyanotype process to create photographic illustrations made without the use of a camera, the result of which is also known as a photogram. The exact process she employed involved placing her specimens directly onto coated paper, which allowed the action of light to create a silhouette effect.

Honing her skill, Atkins produced an extensive collection of photograms documenting algae found only in the British Isles. Her first book, Photographs of British Algae: Cyanotype Impressions, appeared in 1843. It contained over 250 captioned cyanotypes, complete with several pages of text against the iconic Prussian blue paper. By 1850 she produced 12 additional parts in collaboration with her close friend, Anne Dixon. Atkins made her last photographic work, an album entitled Cyanotypes of British and Foreign Flowering Plants and Ferns, in 1854.

Anna Atkins’ painstaking effort to catalog plant life by means of a photographic process demonstrated photography can be both scientifically useful and aesthetically pleasing. But it was her exclusive use of photograms that makes Atkins the first female photographer.

Underwhelming Support

After Akins, the cyanotype process garnered little attention from the photography community, viewed as an inexpensive proofing process rather than a means to create stand-alone works of art. One example during the 1850s came from artists like M. J. Diness, who proofed his collodion wet-plates he made around Jerusalem using cyanotypes. This method is similar to using a Polaroid to confirm the appropriate exposure of medium- or large-format film. But the cyanotype never experienced widespread acceptance. Two likely reasons include:

1.)  The misconception cyanotype has too short a tonal range.

2.)  Its distinctive dark blue color is unsuitable for most subjects.

Despite its rejection by the art world, disciplines of science and structure once again turned to Herschel’s invention as an effective way of copying diagrams. Between the 1870s and 1950s, architects and engineers used this technique to duplicate plans, paving the way for what is now the modern blueprint. Simultaneously, cyanotype blueprints were gradually replaced by diazotypes – or whiteprints – in the early 1940s. These proofs were the inverse of a cyanotype, with blue lines on a white background rather than white lines on a blue background.

A Modern Revival

Around the time architecture phased out the process, contemporary photographers during The Sixties gave cyanotype new life. It served as an alternative to silver gelatin, which dominated photography until the twenty-first century. As the Getty Conservation Institute points out: Digital photography is replacing classic “chemical” photography, making silver gelatin itself an alternative photo process.

Today, a multitude of innovative cyanotype products allow more options than ever to blend digital technology with a photographic method over 175 years old. This process is no longer limited to its signature blue background without the use of toning. Modern variations on Sir John Herschel’s technique enable users to produce work in a variety of colors – with greater tonal range – on surfaces once beyond the reach of traditional cyanotype.


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