BRIEF SUMMARIES OF THE PROCESSES
All of these processes use iron to form the image and all were invented before 1900. The photographer combines two or more chemicals in solution and brushes the liquid on paper, usually a fine 100% rag art paper. Because all of these methods are relatively insensitive to light, the ‘tdarkroom’ work can take place under dim tungsten light. The negative is then placed in contact with the coated paper and the exposure is made using the sun or other light sources rich in ultraviolet (therefore the print is the same size as the negative).
PLATINOTYPE: Key research was by Johann Doebereiner who discovered that platinic chloride could be reduced by light (1826); also found that ferric oxalate was light sensitive (1831). Englishman William Willis took out a patent on the platinotype in 1873 with subsequent patents in 1878, 1880, 1887. He founded the Platinotype Company, a commercial manufacturer of platinum paper in 1879. The soaring cost of platinum after World War I made the process too expensive to use.
The paper is coated with a mixture of ferric oxalate and potassium chioroplatinite, dried and printed. The image is developed in one of several agents, potassium oxalate being the most common. Prints have an extremely long tonal range and are extremely permanent.
PALLADIOTYPE: Very similar to platinotype except employing palladium chloride as the metalic salt. Palladium salts cost about 60% less than platinum salts. The image is more apt to solarize and has a slightly shorter tonal range than platinum but is otherwise very similar. Many artists combine platinum and palladium salts in one print.
KALLITYPE: Patented by Englishman Dr. W. W. J. Nichol in 1889, it combines iron and silver salts to achieve nearly the quality of a platinotype at a substantially reduced cost. There are a large number of variations available but the standard procedure uses ferric oxalate and silver nitrate to form the image. Many developers are available and will influence the color of the final print immensely. Assuming it is fixed properly, a kallitype is as stable as any modem silver process.
CYANOTYPE: Discovered by Englishman Sir John Herschel in 1841-42, this is one of the oldest, simplest, cheapest and most stable photographic printing processes ever invented. An iron salt (usually ferric ammonium citrate) and potassium ferricyanide are coated on paper, dried, printed. Development and fixation are achieved using only water. When well done, a cyanotype has a long tonal range. The chief limitation is that the image is available only in blue which is unsuitable for many subjects.
Each print is hand crafted by hand coating the fine cotton rag paper with light sensitive chemicals (emulsions) It is because of this that each print can be consider one of one
a very limited number of prints is made each one is sign dated and number .
The prints are what is know as contact prints, this means the print is the same seize as the negative.
The papers use to insure permanence of the print are of the finest quality cotton papers available today they are Ph neutral .
The unique look of this prints is due to the methods used unlike silver gelatin prints the emulsion (the Image) becomes part of the paper rather then laying on top of it .
The prints are mounted on 4-ply museum grade rag boards they are then over matted with eight-ply window mat rag board and are signed dated and numbered.