Photographer's Formulary PMK Pyro-Metol Kodalk Film Developer, PMK stands for "Pyro-Metol-Kodalk". Kodak has changed the name Kodalk; to Balanced Alkali; - this is their proprietary name for sodium metaborate.
The formula is constituted to achieve the best overall results in consideration of the following technical criteria: sharpness, maximum image stain, minimum general stain, edge effects, film speed, flexibility for Zone System Plus and Minus development, stability, repeatability, convenience of use and long shelf-life.
The PMK formula was developed by Gordon Hutchings in 1979, and is designed as a universal developer for a wide variety of modern emulsions used under diverse conditions.
PMK is known for it's unique tanning and staining action. This is due to pyro, its key ingredient, PMK provides both exceptional detail and gradation that no other commercial developer can rival, and its ability to separate nearly-adjacent tones (particularly in the highlights) is legendary.
An alkaline fixer solution such as TF-4 is recommended for achieving maximum pyro stain on the negative. A conventional rapid fix may diminish staining effects of pyro and PMK formula The PMK formula consists of two stock solutions.
The "A" stock is the developer agents and the "B" stock is the alkali, or accelerator.
To Make 25 liters of Working Solution