Mordançage
Encyclopedia
Mordançage is an alternative photographic process that alters silver gelatin prints
to give them a degraded effect. The mordançage solution works in two ways: it chemically bleaches the print so that it can be redeveloped, and it lifts the black areas of the emulsion away from the paper giving the appearance of veils. Once the emulsion is lifted, it can then be removed or manipulated depending on the desired outcome. Areas where the emulsion was removed appear to be in relief. These prints can become oxidized during their creation, further altering the tonality of the image.
during the 1960s. While he is credited with the creation of Mordançage, it is based on a late 19th century process known as etch-bleach. This process has also been referred to as bleach-etch, gelatin relief, or reverse relief. Etch-bleach was first documented in 1897 by Paul Liesegang and was originally used as a reversal process for film negatives
. Within a year, a man named Andresen suggested using hydrogen peroxide and hydrochloric acid
in the process in the place of ammonium persulfate
. Later references to the etch-bleach process show a chemical composition that is very close to that of mordançage - the only difference being the use of citric acid
in place of glacial acetic acid. Sudre refined this technique and dubbed it "mordançage." His process has since been adopted by some of his students, and has spread from there.
After cleaning, the print is redeveloped. A variety of fresh or exhausted developers
can be used at various dilutions, as well as some toners. Different developers and dilutions will result in different tonalities in the paper. Areas where the emulsion has been degraded may redevelop unevenly. Emulsion removal can cause a reversal effect when redeveloped. Once the image has been redeveloped, it is rinsed off again. The print can be fixed in fixer
at this point. Neglecting to fix the image can lead to the oxidation of the print, however these color shifts can be a desirable effect.
A final washing of the print is performed after fixing. Any veils that have developed are fragile, which makes the print difficult to wash without causing them to pull away from the paper. Because of this difficulty, mordançage prints will often remain imbued with chemicals. The chemical saturation of the paper can lead to these prints contaminating work areas and other photographs.
While the process often follows this progression, it can be altered. Development of the print can be halted at any point in the process through the use of stop bath
. Alternatively, sometimes prints will be bleached and redeveloped multiple times until the artist is happy with the results.
Gelatin silver print
Gelatin silver prints were the dominant photographic process nearly from the period of their introduction in the 1880s until the 1960s when they were eclipsed by consumer color photography. As such, the gelatin silver or black-and-white print represents a primary form of visual documentation in the...
to give them a degraded effect. The mordançage solution works in two ways: it chemically bleaches the print so that it can be redeveloped, and it lifts the black areas of the emulsion away from the paper giving the appearance of veils. Once the emulsion is lifted, it can then be removed or manipulated depending on the desired outcome. Areas where the emulsion was removed appear to be in relief. These prints can become oxidized during their creation, further altering the tonality of the image.
History
Mordançage was created by Jean-Pierre SudreJean-Pierre Sudre
Jean-Pierre Sudre was born September 27, 1921, in Paris, France. A commercial photographer in Paris, he later moved to the south of France, where he devoted his life to workshops of "fine art" photography. He is known for his experimentation with chemicals as well as for his still lifes....
during the 1960s. While he is credited with the creation of Mordançage, it is based on a late 19th century process known as etch-bleach. This process has also been referred to as bleach-etch, gelatin relief, or reverse relief. Etch-bleach was first documented in 1897 by Paul Liesegang and was originally used as a reversal process for film negatives
Photographic film
Photographic film is a sheet of plastic coated with an emulsion containing light-sensitive silver halide salts with variable crystal sizes that determine the sensitivity, contrast and resolution of the film...
. Within a year, a man named Andresen suggested using hydrogen peroxide and hydrochloric acid
Hydrochloric acid
Hydrochloric acid is a solution of hydrogen chloride in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid....
in the process in the place of ammonium persulfate
Ammonium persulfate
Ammonium persulfate 2S2O8 is a strong oxidizing agent. It is very soluble in water; the dissolution of the salt in water is endothermic. It is a radical initiator. It is used to etch copper on printed circuit boards as an alternative to ferric chloride solution...
. Later references to the etch-bleach process show a chemical composition that is very close to that of mordançage - the only difference being the use of citric acid
Citric acid
Citric acid is a weak organic acid. It is a natural preservative/conservative and is also used to add an acidic, or sour, taste to foods and soft drinks...
in place of glacial acetic acid. Sudre refined this technique and dubbed it "mordançage." His process has since been adopted by some of his students, and has spread from there.
Chemistry
The mordançage solution consists of the following materials.- 10 g copper chlorideCopper chlorideCopper forms two stable chlorides:*Copper chloride , CuCl, mineral name nantokite.*Copper chloride , CuCl2, mineral name eriochalcite....
- 50 mL glacial acetic acid
- 25 mL 30%-35% hydrogen peroxideHydrogen peroxideHydrogen peroxide is the simplest peroxide and an oxidizer. Hydrogen peroxide is a clear liquid, slightly more viscous than water. In dilute solution, it appears colorless. With its oxidizing properties, hydrogen peroxide is often used as a bleach or cleaning agent...
- distilled waterDistilled waterDistilled water is water that has many of its impurities removed through distillation. Distillation involves boiling the water and then condensing the steam into a clean container.-History:...
to make 1 liter
Process
The mordançage process can be used to treat either fiber-based or resin-coated paper. After making a silver gelatin print, the photograph is placed in the mordançage solution, and left in until the image has bleached. The hydrogen peroxide in the solution softens the gelatin in the emulsion. Next, the chemicals are rinsed off of the print. Some people choose to remove the parts of the emulsion that have started to disintegrate while washing; these areas will be the darkest portions of the print.After cleaning, the print is redeveloped. A variety of fresh or exhausted developers
Photographic developer
In the processing of photographic films, plates or papers, the photographic developer is a chemical that makes the latent image on the film or print visible. It does this by reducing the silver halides that have been exposed to light to elemental silver in the gelatine matrix...
can be used at various dilutions, as well as some toners. Different developers and dilutions will result in different tonalities in the paper. Areas where the emulsion has been degraded may redevelop unevenly. Emulsion removal can cause a reversal effect when redeveloped. Once the image has been redeveloped, it is rinsed off again. The print can be fixed in fixer
Photographic fixer
Photographic fixer is a chemical or a mix of chemicals used in the final step in the photographic processing of film or paper. The fixer stabilises the image, removing the unexposed silver halide remaining on the photographic film or photographic paper, leaving behind the reduced metallic silver...
at this point. Neglecting to fix the image can lead to the oxidation of the print, however these color shifts can be a desirable effect.
A final washing of the print is performed after fixing. Any veils that have developed are fragile, which makes the print difficult to wash without causing them to pull away from the paper. Because of this difficulty, mordançage prints will often remain imbued with chemicals. The chemical saturation of the paper can lead to these prints contaminating work areas and other photographs.
While the process often follows this progression, it can be altered. Development of the print can be halted at any point in the process through the use of stop bath
Stop bath
Stop bath is a chemical bath usually used in processing traditional black-and-white photographic films, plates, and paper used after the material has finished developing. The purpose of the stop bath is to halt the development of the film, plate, or paper by either washing off the developing...
. Alternatively, sometimes prints will be bleached and redeveloped multiple times until the artist is happy with the results.