Although pyrogallol (pyro) is the oldest b&w developer and was dominate in the 19th century, it was mostly ignored in the 20th century except for a few photographers mostly on the west coast. About 30 years ago, John Wimberly and I created a resurrection of this developer.

For some time these formulas had to be made in each photographers darkroom. However the formulas proved so popular that several commercial sources are available for both John Wimberly's WD2D and my PMK.

Why would anyone want to use a pyro developer in preference to conventional developers? There cannot be a universal answer to this question. To determine the usefulness of any developer we have to ground ourselves in our prints. Take a good hard look at your prints. Are you satisfied with them, technically? If the answer is yes, you need go no further. Some photographic expressions or styles may not benefit from a different developer.

If you are shooting "fine art" photographs, particularly "west coast" style landscapes or portraits and weddings then you may want to push your technique a little harder and try a pyro developer. Particularly if you are not satisfied with highlight separation and a general crispness to the prints.

About 30 years ago, when I first began to teach workshops in pyro, a San Francisco portrait and wedding photography actually offered me money if I would keep the PMK formula a secret. Whether it was a real offer or not, I am not sure, but his desire to keep a distance between himself and other bay area photographers was clear.

What he saw in his wedding pictures was a lovely separation of the white on white tones of typical wedding pictures. Wedding dresses, cakes, table cloths, snow scenes or what have you in the white department separate beautifully with ordinary printing skills. No heroic efforts and stomping all over the prints are necessary.

In addition to the highlights printing effortlessly, the mid-tones have a platinum like luster and the shadows are deep and illuminated easily.

This is all because of a set of characteristics of film that is developed in a staining pyro developer. In a staining pyro developer like PMK the oxidation products of the silver halide reduction stain and harden the film gelatin immediately at the silver halide development centers. The tanned gelatin has a yellowish green stain color and the color density as well as the neutral density of the stain both increase with increased exposure. The total density of the negative is the combined density of the reduced silver plus the neutral density of the stain.