The salt print is one of the earliest forms of photographic print dating back to 1830s when Henry Fox-Talbot invented and refined the process. A sheet of paper is coated with a solution of sodium chloride and once dry, a coating of silver nitrate solution is applied. These chemicals react to become silver chloride, a compound sensitive to ultraviolet light.
A print is created by sandwiching the coated paper with a negative the size of the final image in a contact printing frame and exposing to UV light. To achieve large prints digital negatives printed on transfer film are used and each digital negative is optimised for the process. Prints are then developed in a salt solution, toned and fixed.
Toning a salt print in a platinum solution achieves a subtle and beautiful range of tones and also adds archival permanence to the print.