The quality of processing is a very important factor in image stability. Improper processing can result in deterioration of the image. This section also covers the use of toners for protecting black-and-white images.
Incorrect processing procedures such as faulty agitation, insufficient or excessive fixing, and inadequate or excessive washing, can result in defects after long-term storage that were not apparent shortly after processing. Other guidelines include avoiding contamination of solutions, using proper replenishment, minimizing oxidation of developers, cleaning the tanks regularly to avoid bacterial growth, and using a stop bath when recommended.
Despite all precautions, a photographic image is still subject to deterioration caused by many external factors. Prints and negatives can be affected by exposure to high levels of light for extended periods, or by adverse storage and display conditions. You can help to protect black-and-white prints and some films by treating them with a toner such as KODAK Rapid Selenium Toner, KODAK POLY-TONER, KODAK Sepia Toner, or KODAK Brown Toner.
Toner treatment will protect an image whether it produces a hue shift or not. For long-term protection without a tone change, choose an appropriate combination of paper, developer, and toner. For example, one combination that will give protection without a tone change is KODAK ELITE Fine-Art Paper processed in KODAK DEKTOL Developer and toned in KODAK Rapid Selenium Toner diluted 1:20 or 1:40.