A chemigram is an experimental piece of art where an image is made by painting with chemicals on light-sensitive paper.
First page of the Bayard album, photosensitization test, 1839, collection of the Société française de photographie.
Josef H. Neumann Chemogramm *Traumarbeit* (1976)
A chemogram is an experimental art where a photographic image is partly or fully enlarged and processed onto photographic paper in the darkroom and afterwards selectively painted over in full light with chemicals used in photographic processing. Due to the production process chemograms can be considered works of abstract photography.
Josef H. Neumann: Gustav I (1976)
Josef H. Neumann:Trocadero Paris (2017)