Photographic printing

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Photographic printing is the process of producing a final image on paper for viewing, using

Following exposure, the paper is processed to reveal and make permanent the latent image.

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

Kodak has announced that it will no longer produce or sell this product.^[when?] However, as of 2006^[update], it is still available from various online retailers.

Silver mirroring

Silver mirroring, or "silvering", is a degradation process of old black-and white-photographic prints caused by conversion of the black silver oxide to silver metal. This results in a slightly bluish, reflective patch in the darkest part of a print or negative when examined in raking light. It often indicates improper storage of the prints.^[3]

Printing on coloured paper

For more info see also: Chromogenic print

Colour papers require specific chemical processing in proprietary chemicals. Today's processes are called

• Colour negatives are printed on
  colour negative films in that they consist of three emulsion layers, each sensitive to red, green and blue light. Upon processing, colour couplers produce cyan, magenta and yellow dyes, representing the true colours of the subject. The processing sequence is very similar to the C-41 process.^[4]
• Rollei makes a film called 'Digibase 200 Pro' that is like a conventional C-41 film but it has no orange mask, allowing easy prints on black-and-white paper with a grade 2 or 3 variable contrast filter

See also

• Contact print
• Film developing
• Gelatin-silver process
• List of photographic processes
• Photographic paper
• Photographic print toning
• Standard photographic print sizes