Formulated by Gordon Hutchings as a "universal developer," Bergger PMK Film Developer is a pyro staining developer characterized by its versatility and the distinctive yellow stain it leaves on the film. This developer offers high sharpness and very fine grain, along with high stability and low base fog. It is delivered as two separate solutions in order to prolong the effective shelf life. When mixed and diluted, they can make 25L of working solution. Additionally, this pyro developer requires the use of an alkaline fixer in order to obtain the best negative stain and maximum stability.