Chemicals for c-41process

 

Colour Developer



In general, film processors designed for C41-RA-NP, are configured for low rate colour developers such as (CD-LR). However, if the workload is low we recommend that the alternative C-41 standard developer (CD-R)  - see: http://www.photo-chemicals.com/  be used to improve the stability of the process. Conversely, if the workload is very high, the use of colour developer super low rate (CD-SLR) enables more economical working with considerably reduced overflow and packaging waste. To change from one to another type of developer is very easy and does not need replacement of the working tank solution. It only requires changing the replenishment rate on the processor to the value for the new type of developer replenisher used. To make a fresh tank of working solution, add water and the appropriate developer starter to the mixed replenisher. (Refer to mixing instructions) Attention should be paid to the following: the starter for CD-SLR is different to the starter used for CD-R and CD-LR.
In modern processors, evaporation loss in the working solution is compensated for by an automatic water addition system. If no automatic system exists, then compensation must be made manually. Without water compensation the concentration of the working solution increases leading to over development and to deviations in process stability.

 

Bleach


Bleach BL-RA, is supplied as a ready-to-use replenisher solution. No mixing or water addition is required. When making a Bleach working tank solution, water and bleach starter need to be added to the BL-RA replenisher (refer to mixing instructions). To maintain the efficiency of the bleach, the working solution must be aerated. The aeration should be set at a rate that creates surface bubbles, but without excessive foaming. Evaporation must be compensated for by the addition of water, either manually or through automatic water top up systems. Without evaporation compensation, the concentration of the working solution continually increases resulting in crystallisation.



Fixer


Fixer FX-RA is supplied as a concentrate. The replenisher and working tank solution is prepared by mixing the concentrate with an equal amount of water. No starter is required for the tank solution. The normal tank configuration is two in cascade running counter-current. Evaporation must be compensated for by the addition of water, either manually or through automatic water top up systems.



Stabilizer


The C-41 RA NP process uses the stabilizer STAB-BNP in a cascade consisting of 3 working tanks running counter current. Working solution and replenisher are identical and no starter is required for the tank solution. The replenisher is prepared by mixing STAB-BNP concentrate with water. Evaporation compensation is essential. Without this compensation, the concentration of the working solution increases resulting in the formation of flow lines on processed films.