Photographers' Formulary 01-5060 PMK Film Developer Formerly known as Kodalk Highly suited for use with the Zone System Long shelf life PMK Pyro is a staining-type developer which yields fine grained negatives with superb sharpness and highlight detail The 50-liter PMK Liquid Kit is supplied as one-half liter of stock solution A, and one liter of stock solution B to make 50 liters working solution An alkaline or pH neutral fixer is recommended for achieving maximum pyro stain on the negative. A conventional rapid fix may diminish staining effects of pyro and PMK formula.