Art Term Tuesday: Mordançage

Katy Thompson, Associate Director of Education

With The National: Best Contemporary Photography 2022 currently on display, we’re taking a deep dive into the diverse processes and techniques used to develop and print photographs. In a previous “Art Term Tuesday” we discussed the difference between silver gelatin and archival pigment prints, or fine art photographs. Today, we’re taking it a step further and delving into a more specialized method: mordançage.

Kristoffer Johnson, American, b. 1990. To Which We Return: Untitled No. 143. Mordançage; Silver gelatin print, 2021. Loan from the Artist. Image courtesy of Kristoffer Johnson.

Starting with a black-and-white silver gelatin print, mordançage uses chemicals to alter the surface of the photograph and create a degraded or veiled effect. Essentially, the artist redevelops the photo by chemically bleaching it, lifting the black areas away (partially or completely) to play with tonality and create the illusion of relief. Pioneered in the 1960s by Jean-Pierre Sudre, it is based on a late 19th century reversal process for film negatives called etch-bleach (sometimes referred to as gelatin or reverse relief).

While the silver gelatin print is usually the finished product, in this case it is the starting point. Submerged in the mordançage solution (copper chloride, glacial acetic acid, hydrogen peroxide, and distilled water), there are various steps that influence the degree of emulsion lift and corresponding veils, including the type of photographic paper, time submerged in the solution, and the concentration of each ingredient in the solution. Once the desired concentration and time spent submerged (more time=more lift) is decided, the photograph is left until bleached. The acid-copper bleaching dissolves the darker parts of the silver gelatin, lifting it away from the print. Once lifted, those areas are either rubbed away, creating a reversal of the image, or retained for their veiling effect. The solution is rinsed off using a water bath and the print is redeveloped to restore the black color. It is then pressed flat and left to dry.

While art and science are often seen as opposing entities, here it is crucial for the artist to become scientist (or vice versa) to ensure the print turns out as planned. First, an artist must decide if their photograph lends itself to mordançage. The darker the original the better, since it is the darker areas that experience more dissolution. The artist must also determine their chemical solution; for example, the copper chloride is integral for the initial bleaching but the hydrogen peroxide softens the gelatin during the bleaching. Partnering with the acetic acid, the hydrogen peroxide softens the photographic paper which allows the copper chloride to seep in and oxidize. Now silver chloride, the surface layers lift and veils appear. During redevelopment, the veils darken again as the silver chloride returns to metallic silver. Even the type of paper, or substrate, plays a role in reaction. Cotton-rag is most permeable, giving the artist the most dramatic reaction, in comparison to resin-coated and fiber-based papers. Therefore, a cotton-rag substrate with a long soak in the chemical bath will result in a more pronounced veiling effect. How long do you think Kristoffer Johnson left his print to soak?

Based in Arkansas, Johnson draws from the Buddhist meditation maranasati (mindfulness of death) and the Western visual tradition of memento mori (remember that you must die) in his To Which We Return series. The series focuses on the impermanence and fragility of the human body and the physiological problems that are inherent in existence. Maranasati invites one to visualize and contemplate their body in a state of decay. What happens when the veil is lifted and we die? Using mordançage, Johnson externalizes this visualization through the cracked photo surfaces and emulsion veils, weighted down by gravity, to visually reference the collapse and declining entropy of the human body.

To see what other methods contemporary photographers are using, check out The National: Best Contemporary Photography 2022 at FWMoA now through January 22, 2023.


Interested in the science? You can read more in a study done by Caroline Fudala and Rebecca M. Jones, The Chemistry of Mordançage, a Historic Photographic Process in Analytical Chemistry. 2019 Nov. 19, 91 (22): 14482-14488.

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