Palladium-toned kallitype taken by William Lawrence in 2015. Artist's proof 2 of 2, 11" x 14".
What is the kallitype process?
The kallitype process was invented by Dr. W. W. J. Nicol in 1889. This process uses a combination of a light-sensitive iron compound as well as a silver compound to make an image with exposure to light. It has it's origins in iron-based processes similar to cyanotypes, and has some similarities to the platinum/palladium printing process. I mix the iron and silver compounds, and paint the base paper with the resulting mix. Once the paper is dried, a negative is placed on top of the light sensitive paper in a glass printing frame, and then placed under high-intensity UV light. When the exposure is complete, the exposed print is developed toned with a metal, and fixed. I use gold or palladium as a toner, which gives the tonality that I want, and also greatly increases the longevity of the prints - there are still toned kallitypes around today from when the process was used in the 19th century. The print is washed to remove unused chemicals, then dried.
These kallitypes are hand-made. Since each print is individually made with a historic process using hand-mixed chemistry, individual prints from the same negative may show variation.