Collodion Negative

Page Information
Date initiated	December 4, 2022
Contributors	Katherine Miromonti, Luisa Casella

Collodion Negative

Historical Facts

Invented: Gustave Le Gray (1851), Frederick Scott Archer (1851), Jean-Marie Taupenot (1856)
Patented: Murray Alexander, Eastman Kodak Co (1930-1950)
Historic Practitioners: Frederick Scott Archer, Roger Fenton, Alexander Gardner, Charles Bayliss, Bernhard Otto Holtermann
Contemporary Practitioners: Sally Mann, Ben Cauchi, Borut Peterlin, Joni Sternbach, Jill Enfield, Craig Murphy, Lindsay Ross, Simon Riddell

After the success of the daguerreotype and calotype in the 1840s, innovators in the field of photography began looking for ways to further improve the medium. This came in the form of the wet collodion photographic process in 1851. The wet collodion process produced a great deal more detail than daguerreotypes or calotypes and allowed photographers to print an unlimited number of copies. The process remained the leading photography well into 1880s, when it was replaced by the gelatin silver process, which was equally sensitive but had long lasting, portable glass plates.

Invention

The inventor of the wet collodion process is highly debated. Some suggest that the process was developed by Gustavo Le Gray between 1850 and 1851. Le Gray, a trained painter and innovator in the field of photography, allegedly began experimenting with coating his plates in collodion––solution of nitrocellulose in a mixture of alcohol and ether––to sharpen the clarity of his images. However, his method was received as "theoretical at best" and he abandoned the coated glass plate method to pursue paper methods of photography, where he believed the future of the field lay.

Frederick Scott Archer is more frequently credited with the invention of the wet collodion plate process. An amateur photographer, Archer spent the last few years of the 1840s experimenting with ways to produce a sharper image in a shorter amount of time. By 1851, he was practicing and teaching his wet collodion process. Archer's method involved applying a layer of collodion to a clean glass plate, then immersing it in a bath of silver nitrate to activate its photosensitivity. Once the plate was inserted into a camera, capturing a negative image only required a few seconds.

While Archer's collodion wet plate method had many advantages, including the efficiency of capturing the negative and the sharpness of the resulting image, it also has several serious disadvantages. First, the glass plate had to be developed in less than 10 minutes after it was exposed; otherwise, the collodion would become impervious to the processing solution once the alcohol and ether dried. This was not an issue for photographers who worked in studios, for example, portrait photographers. However, the mid to late 1800s saw a rise in battlefield photography coinciding with the Crimean War and United States Civil War. Photographers could transport a dark room on site if necessary, but it was not easy as the equipment and materials needed to produce a negative weighed around 250 kilograms.

Dry Plate Method

In order to preserve collodion wet plates for transportation back to the photography studio, many photographers experimented with adding hygroscopic materials or preservatives such as sugar, tannin, glycerin, or dextrin to the collodion solution. These methods were referred to as "dry plate" because they did not require the same amount of wet preparation as the original collodion glass plates. In 1856, Jean-Marie Taupenot adapted the collodion process by sealing the collodion layer with albumen, which allowed the plates to remain in their sensitized state for weeks. Unfortunately, these early experiments often reduced the sensitivity of the collodion plates, and development took significantly longer, sometimes up to twelve hours.

In 1867, the Liverpool Dry Plate Company started marketing a new collodion dry plate. Instead of coating the glass plate with collodion and then dipping it into a silver nitrate solution, the new plate was coated with a collodion emulsion containing fully formed photosensitive silver compounds. Although sales were not particularly successful, this new product reduced the number of steps required before an image was captured and set a precedent for how the photography field would continue to develop.

Contemporary Practice

Collodion negatives and prints have seen a resurgence in the 21st century in fine art photography and Civil War Reenactment photography. New York-based artist Richard Barnes utilizes the collodion technique to capture the aftermath of battles and portraits of long-dead historical figures in addition to exploring topics of science, archeology, and architecture. Sally Mann, who learned the collodion process from France and Mark Osterman, explores family, memory, and decay through her collodion prints. In 2020, Simon Riddell, a photographer currently working in Victorian wet plate methods, began a collaborative project called Mental Collodion which focuses on mental health and emotions during the first phase of COVID-19.

Identification Characteristics

Wet Collodion negative structure diagram

Materials

Collodion wet plates are coated with a layer of collodion, which acts as a binder for photosensitive silver compounds. Collodion is produced by dissolving pyroxylin, a form of nitrocellulose, in alcohol and ether. Pyroxylin is created during the treatment of cellulose from cotton or wood with a mixture of nitric and sulfuric acids.

Some early photographers experimented with adding sugar, tannin, glycerin, or dextrin to the collodion to prevent it from drying too quickly. However, once the photos are printed and the plate is dry, it is virtually impossible to tell the difference between plates that contain preservatives and those that do not.

It is also common for photographers to varnish their collodion negatives to protect them from scratches and abrasions. Varnishes for collodion negatives are typically natural resins dissolved in solvents; however, the plates must be pre-coated with aqueous solutions like gum Arabic, dextrin, albumen, or gelatin to protect the collodion binder from dissolving when contacted by the alcohol in the varnish.

Test by Mark Osterman of a study collection piece demonstrating solubility of collodion to different solvents

Color

Collodion negatives can display a wide range of tones and colors: creamy white, neutral gray, black, red, tan, olive green, caramel brown, and dark brown. Collodion negatives are easily mistaken for gelatin negatives; however, careful analysis of tones and color are the best way to distinguish the two processes visually. The appearance and color of the negative is dependent on several factors, including the developer, condition of lather, varnish, toners, and whether the negative is viewed via transmitted light or on a light or dark background.

Support

Soda lime silicate glass ranging in thickness from 3.175-6.35 mm is the most common support for collodion negatives. The plates are typically hand-cut, often have rough edges, and may also have slightly irregular shapes.

Collodion glass plates are coated by hand, which often results in an uneven thickness of the collodion layer. Other anomalies that result from the photography process include the presence of the photographer's fingerprints in one corner of the glass plate and the absence of binder on all four corners of the plate where the plate touches the camera’s plate holder.

Conservation

Common condition issues of collodion negative plates include:

• Silver mirroring
• Fading
• Discoloration
• Deterioration of silver image, binder, varnish and/or support
• Weeping glass
• Crystalline deposits on glass
• Moist droplets on emulsion
• Mechanical damage (e.g. cracking, abrasions)

Housing and Storage Considerations

Housing and Storage

Collodion negatives are sensitive to light, abrasion, humidity, and excessive water and should be stored in a cool, dry place. It is best to store the glass plates individually in envelopes placed in custom boxes. It is safer to place the plate vertically, but they can be store in small horizontal stacks if there is no other option.

Exhibition

There are several challenges that come with displaying photographic negatives of any kind, including collodion negatives. Backlit window mounts are useful for increasing visibility of photographic negatives; however, light can be damaging to negatives and needs to be carefully monitored. Reducing the light level and protecting the negative in a window mount is another potential protective method. Encasing the negative in glass or plastic also protects the image and support from abrasions and surface grime. To learn more about displaying photographic plates, visit the PMG Cased Photographs page.

References

Lavédrine Bertrand, Jean-Paul Gandolfo, John McElhone, and Sibylle Monod. “Chapter 7: Negatives on Glass.” Essay. In Photographs of the Past: Process and Preservation, 234–45. Los Angeles, CA: The Getty Conservation Institute, 2009.

Reilly, James M. “Collodion.” Essay. In Care and Identification of 19th-Century Photographic Prints, 28. Rochester, NY: Image Permanence Institute, 2009.

“Wet Plate Collodion Identification.” Graphics Atlas. http://www.graphicsatlas.org/identification/?process_id=352#objectview.

Further Reading

Lundgren, Adrienne. Magnificent Intentions: John Wood, First Federal Photographer (1856-1863). Smithsonian Institution Press, 2024.

Graphic Atlas: Wet Plate Collodion Overview

Khan Academy: The Wet Collodion Process Demonstration

The Dry Collodion Process by Charles A. Long

The Silver Sunbeam: Collodion Negatives, Dry Collodion Processes, Imperfections and their Remedies

Treatise of Photography on Collodion

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