Black and White Print Process

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Process Times for Black and White Prints

Process Sequence for Black and White Prints

Process Information for Black and White Prints

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Process Times for Black and White Prints

• Rotation Speed (with reversing directions) 'P'/75 for 1500 and 2800 drums, '4'/50 for 3000 drums
• Temperature 20°C (68°F)

1. Pre-Rinse 0:30
2. Developer 1:30 (Time will vary with choice of developer and paper)
3. Stop-Bath 0:30
4. Fix 1:00 (Time will vary with choice of fixer and paper)
5. Rinse 2:00 (4x 0:30) (see note below)
6. Dry As needed.

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Process Sequence for Black and white Prints

Pre-Rinse
The drum and paper are brought to process temperature. The emulsion is completely soaked with water.

Developer
Exposed silver salts are converted to metallic silver. Density and contrast are determined in the developer.

Stop-Bath
The stop-bath quickly and evenly ceases development. The emulsion is made acidic for the fixer.

Fixer
The fixer removes the unconverted silver salt.

Final Rinse
This rinse removes the fixer from the emulsion. Removal of the fixer is necessary for image permanence.

The rinse should be a series of 30-second changes of water. The 2:00 rinse would be four complete changes of water. Each change of water should be about 1 1/4 to 1 1/2 times the volume of chemicals used.

Dry
As needed.

Both the developer and the fix times will vary with the manufacturer's directions for the use of their product. For optimum results, select a paper developer type and dilution that has at least a one minute development time at the processing temperature used.

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Process Information for Black and White Prints

Making prints from negatives. The JOBO processor can also be used for papers and chemicals manufactured by Kodak, Ilford, Agfa, Oriental, etc. JOBO also has a line of black and white chemicals made by Tetenal.

JOBO does not recommend processing Fiber Based print paper in our print drums. The raised ridges on the inside of the drums may mark the paper, and rinsing in the drum may not be satisfactory.

It is good practice to be consistent in processing procedures. However, it may be useful to know that with the exception of the developer (or toner, if used), all steps in the black and white resin coated print process are 'taken to completion.' That is, once the action of the chemicals or rinse has done what it is supposed to (had its effect), further time in the bath or rinse will have no additional benefit or harm. If you are to error in the timing of the process steps other than the developer (or toner, if used), it is safer to go longer, not shorter. Be aware however, that very long (over 20 minutes) immersion times for resin coated paper in any solution or water could cause frilling or discoloration at the edge of the paper and other problems, and should be avoided.

JOBO paper drums have a chemical quantity printed on the side stating the minimum amount required to cover the paper during processing.

With black and white prints, there is no chemical (at recommended dilutions) that would require more solution quantity than printed on the drum. It is safe to use the quantity printed on your JOBO Drum. If you are using extended dilution of the processing chemicals, check with the manufacture's quantity requirements. In all cases use at least the volume required by the print drum or the chemical-dilution used.

You may add toning procedures to the black and white print process in your processor. Follow the manufacturer's recommendations on times for the additional steps.

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