Reggie with peacock feathers
High contrast positive & negative sandwiched together and
contact printed on another piece of film to make another negative,
and then that negative printed on photo paper. (89k jpeg)
First of all, just printing an image on high contrast paper, or copying it on to high contrast film, can change it or enhance it a great deal. Beyond that, many interesting effects may be obtained by making high contrast negatives and positives of an image and then sandwiching them together and printing the sandwich.
There is a bewildering variety of high contrast films to choose from, and for artistic purposes, any will do. I get whatever is cheapest.
Ortho line film is high contrast film you use with a red safelight. It comes in large sheets (about 8 inches x 10 inches, up to 20 inches x 24 inches; also in rolls) which is useful for making negatives for gum, brown and blueprints. Litho or printers' supply companies, and some blueprint companies and camera stores carry ortho line film or can order it. See the links on the Alternative Photography page.
Exposure High contrast Ortho film is easy to expose and process. You can make small negatives, such as 35mm or 2-1/4, by contact printing your negatives or transparancies onto ortho film, although dust and blemishes might be a problem when you work small (or they can add to the art). You can enlarge negatives and slides onto sheets of ortho film in your enlarger, with sheets of film in the enlarger easel just like you would use paper. You can also make photograms or use it in pinhole cameras. Reversal film will give you negatives from positive transparencies, and positives from your negatives.
Processing Follow the film manufacturer's processing instructions, and if you don't have an instruction sheet, make test exposures on small pieces, and develop the film in A and B developer, Rapid Access or other high contrast film developer, in a tray for about 2 minutes at 68 degrees F.
Rinse in running water about 30 seconds, and fix with agitation for a few minutes. Time how long it takes for the film to clear in the fixer (say, 2 minutes) and then leave it in that time again (in this example, 4 minutes total). Wash for about 20 minutes in running water, and hang to dry.
The resulting positives and negatives can be contact printed or projected in an enlarger.
For positive/negative sandwiches, make a negative and when it is dry, contact print it onto another piece of film to make a positive. Then put the positive and negative together, and print it on paper; or contact print the positive-negative sandwich onto another piece of film, and then print it on paper. It's not as complicated as it sounds!
Sometimes the image is more interesting if the positive and negative are out of register.
Pocket Pal A Graphic Arts Production Handbook, International Paper Company, International Paper Plaza, 77 West 45th Street, New York, NY 10036.
Includes halftones and registration, along with type, inks, paper, printing processes, etc.
My copy, the 12th edition, was published in 1981 but I think there are newer editions out.
Patterns from dust and dirt. 35mm negative made from positiv/negative sandwich, from original 35mm slide. On small pieces of film, dust specks become magnified. The film was also somewhat fogged (partly from age and partly during processing), resulting in solarized background and dust images. (62k jpeg)
Accidental Pattern. Copy negative was left outside overnight in contact with a damp blueprint. The chemicals ate away at the emulsion. This could be used for background patterns and other special effects. (83k jpeg)