The catechol developer works slowly with a more contrasty gradation. It is to be used as the first developer in two-bath processes. The exposure time is tested with the second developer. Develop in the catechol until the shadows are clearly visible. Depending on the dilution, this takes 50 to 90 seconds. Then develop in the second bath until the desired highlights are visible. The shadow densities are increased and clearly separated, the image tone of the second developer is shifted to cooler nuances, the longer the print remains in the first developer. This can be used specifically to deepen the blackening of shadows in very warm paper/developer combinations. In this case, change to the second developer as soon as the image trace appears.
Shelf life of concentrate 2-3 years, after opening approx. 1 year depending on the filling level.
Shelf life of working solution 1-2 months
Capacity per litre concentrate approx. 200 sheets 24x30cm