Developer · Black and white
DIY/Homebrew PMK Pyro
AvailableB&WLiquid Concentrate
Also known as: PMK, Pyrogallol-Metol-Kodalk
Gordon Hutchings' pyrogallol-metol formula (The Book of Pyro); the Photographers' Formulary sells it as a two-solution liquid kit. Formulary times are given at 70 F and 80 F (21 and 26.7 C) with 68-70 F the conventional temperature. The stain acts as a contrast mask; pyrogallol is toxic.
- Type
- Liquid
- Process
- B&W
- Temperature
- 20°C
- Dilutions
- 1
- Shelf life
- Stock solutions: indefinite; partly filled stoppered bottles last for years (Photographers' Formulary)
18–26.7°C (64–80°F)
concentrate
Characteristics
GrainFine, level 1 of 3
AcutanceVery high
ContrastCompensating
Extraordinary highlight separation with proportional staining
Dilutions
| Ratio | Use | Notes |
|---|---|---|
| 1+2+100 | One-shot | 1 part A + 2 parts B + 100 parts water (Formulary). Use at least 300 ml of developer per 80 square inches of film. |
Shelf life
- Concentrate
- Stock solutions: indefinite; partly filled stoppered bottles last for years (Photographers' Formulary)
- Working Solution
- One-shot: use once and discard
One-shot developer: at least 300 ml per 80 square inches of film (one 36-exposure 35mm roll or four 4x5 sheets) must be in the tank or tray.
Development times
| Film | Dilution | ISO | Time | Temp |
|---|---|---|---|---|
| FP4 Plus | 1+2+100 | 100 | 10m | 21.1°C (70°F) |
| HP5 Plus | 1+2+100 | 400 | 13m | 21.1°C (70°F) |
| HP5 Plus | 1+2+100 | 400 | 8m | 26.7°C (80°F) |
| Ilford Delta 100 | 1+2+100 | 80 | 11m | 21.1°C (70°F) |
| Delta 400 | 1+2+100 | 320 | 12m | 21.1°C (70°F) |
| Tri-X 400 | 1+2+100 | 260 | 14m | 21.1°C (70°F) |
| T-Max 100 | 1+2+100 | 100 | 12m | 21.1°C (70°F) |
| T-Max 100 | 1+2+100 | 100 | 9m | 26.7°C (80°F) |
| T-Max 400 | 1+2+100 | 400 | 15m | 21.1°C (70°F) |
Often used for
Large format photographyHigh-contrast scenesAlternative process printing (Pt/Pd)Maximum sharpness
Limitations & warnings
- Pyrogallol is toxic - handle with care
- Staining can affect scanning
- Must mix from raw chemicals or buy kits
- Requires precise technique
Descriptions combine manufacturer specifications with community experience. Subjective assessments reflect common sentiment among photographers and may not match your results.