Mordançage

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.

[2] Within a year, a man named Andresen suggested using hydrogen peroxide and hydrochloric acid in the process in the place of ammonium persulfate.

[6]: 314  Sudre's American student, Elizabeth Opalenik, created what is now known as the "draping effect" in the Mordançage process.

After making a silver gelatin print, the photograph is placed in the mordançage solution, and left in until the image has bleached.

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.

Neglecting to fix the image can lead to the oxidation of the print, however these color shifts can be a desirable effect.

[9] Photographs that have not been properly fixed and washed can shift color over time through oxidation and acid migration.