Christina Anderson (USA) - mordançage and chromoskedasic prints
In the mordançage process, a caustic, acidified copper bleaching solution is used to alter a traditional black and white print. The solution bleaches and dissolves away the silver gelatin where blacks occur in the image. Theblacks lift, veil, and disintegrate. They can be artfully arranged and left attached to the print or rubbed off completely. The print is redeveloped after the bleach-etch bath in paper developer or toner, or merely left undersunlight to create unusual colors of mauves, purples, and terra cottas depending on the paper. Each print is unique and irreproducible.
A freshly developed but not yet fixed black and white print is put in two mild photographic solutions, an activator (dilute potassium hydroxide) and a stabilizer (acetate buffered thiocyanate), both in and out of light. Colors appear on the normally monochrome black and white paper where there is white in the print: orange, brown, yellow, pink, purple, green, blue, and silver. The colors are the result of the "Mie" effect; the silver particles become different sizes with exposure to chemicals and light, which in turn scatter light in different ways. Smaller particles are more yellow; larger particles are more red. This process can also be done on an already developed and fixed print, as in the Halochrome process but the colors appear in the black areas of the print only. The print is first bleached in a copper bleaching bath and then redeveloped in the Halochrome bath. In this method, the colors and metallic silver appear in the black areas of the image because that is where the only remaining silver is, as the silver has been previously fixed out of the whites.
Sabrina Biancuzzi (F) - photogravure
Photogravure is a photo-mechanical process whereby a copper plate is coated with a light-sensitive emulsion which has to be exposed to a film positive, and then etched, resulting in a high quality print that can reproduce the detail and continuous tones of a photograph.
Claude Bouchez (F) - from the project "maillots de corps ", cyanotypes
Jean Daubas (F) - Van Dyke brown print.
Albert-Edouard Drains (B) dit Alexandre (1855-1925) - contemporary platinum-palladium prints
Well known pictorialist platinum photographer, Alexander collaborated with the painter Ferdinand Khnopff who, after colorizing a platinum portrait of FK's sister, took all the credit for the ensuing work and considered Alexandre as a mere executioner, which seemed to be standard procedure at that time!
During the restoration of a collection of Alexander's black and white 9x7cm glass plate positives, copied from his platinum prints, from the Cinquantenaire Museum in Brussels, we had the occasion to make 18x24cm negatives, which were printed with the platinum - palladium process, the standard dimension used by Alexander. The outstanding print of this collection is titled: "Anatomy lesson" which is derived from Rembrand's painting with the same name.
Roger Kockaerts (B) - from the project " Endangered plants", mixed media.
A tribute to Anna Atkins (1799 - 1871). The history of photography reminds us that Anna Atkins has published the first book illustrated using photography by utilizing the newly discovered cyanotype process invented in 1842 by Sir John Frederick William Herschel (1792-1871), the famous astronomer, chemist and mathematician.
The cyanotype process, based on the photosensitivity of iron salts, was principally used by Herschel to make copies of his notes as well as photo-grams of peacock feathers and other natural objects. This printing method had been experimented as early as 1834 by William Henri Fox Talbot (1800 - 1877) who made photo-grams with his salted paper process which he called photogenic drawings.
By corresponding with William Henry Fox Talbot, Anna Atkins learned about photogenic drawings, and her acquaintance with a friend of her family, Sir John Herschel, the inventor of cyanotype, gave her access to the printing technique of the cyanotype process.
In 1841, William Henry Harvey (1811 - 1866) an Irish botanist who studied algae, published A Manual of the British Marine Algae which contained extensive descriptions of the seaweeds in question but without individual illustrations. Anna Atkins undertook a photographically illustrated version of the Manual of British Algae before 1843 by using the cyanotype process to produce detailed images of the botanical specimens. Her first publication of 1843 pre-dated Talbot's Pencil of Nature of 1844. Her book entitled Photographs of British Algae: Cyanotype Impressions, containing 424 cyanotypes was issued in several parts over ten years.
The present project has no such encyclopedic ambitions but is constructed around a series of conceptual pieces around the central theme of endangered species, in this case, plants which are in danger of forever disappearing. Roger Kockaerts uses the cyanotype process as a reminder and a tribute to the early photographic images of Anna Atkins.
Pierre-Louis Martin (F) - mordançage
Francis Schanberger (USA) - anthotypes
It is possible to print photographs using nothing but juice extracted from the petals of flowers, the peel from fruits and pigments from plants. In 1842, Sir John Herschel produced a paper entitled - "On the action of the rays of the solar spectrum on vegetable colors, and on some new photographic processes." His experiments used solutions derived from such simple sources as plants and flowers. The use of flower juice as a medium, later referred to as anthotype (from the Greek for flower) has some interesting possibilities.
Extraction of juice from flowers may be carried out by pulping the petals either with a little de-ionised water or alcohol. This can be done with a small pestle and mortar, or similar device. The resulting liquid is a colored tincture, which may then be used for coating the paper. The images are obtained by contacting the subject directly onto the paper, just as photograms or contact prints are produced. For reasonable anthotypes to be produced, depending on the tincture involved, the frame needs to face directly into the sun. Some strong direct sunshine, in the order of 2 to 3 days to 2 to 3 weeks is required, or even more if the sun is intermittent with slight cloud cover. An overcast sky is not recommended for this process, as it needs some good strong sunshine.
Studio Baxton (B) - wet collodium
Gilbert Strouven (B) - color gum