Printing on black-and-white paper
The process consists of four major steps, performed in a photographic darkroom or within an automated photo printing machine. These steps are:
- Exposure of the image onto the sensitized paper using a contact printer or enlarger;
- Processing of the latent image using the following chemical process:
- Development of the exposed image reduces the silver halide in the latent image to metallic silver;
- Stopping development by neutralising, diluting or removing the developing chemicals;
- Fixing the image by dissolving undeveloped silver halide from the light-sensitive emulsion:
- Washing thoroughly to remove processing chemicals protects the finished print from fading and deterioration.
Optionally, after fixing, the print is treated with a hypo clearing agent to ensure complete removal of the fixer, which would otherwise compromise the long term stability of the image. Prints can be chemically toned or hand coloured after processing.
Kodak Panalure is a panchromatic black-and-white photographic printing paper. Panalure was developed to facilitate the printing of full-tone black-and-white images from colour negatives – a difficult task with conventional orthochromatic papers due to the orange tint of the film base. Panalure also finds application as paper negatives in large format cameras. It is generally not suitable for conventional black-and-white printing, since it must be handled and developed in near-complete darkness.
Kodak has announced that it will no longer produce or sell this product. However, as of early 2006, it is still available from various online retailers.