Contact print
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A contact print is a photographic image produced from a film negative.
An exposure box device called a contact printer is used within a light controlled space called a darkroom.
The negative is placed in intimate contact with a sheet of sensitized photographic paper. This is then placed, negative down, onto a top transparent glass plate of the exposure box. Within the box and below the top plate is a translucent light diffuser made from frosted glass. Below the diffuser is a switch controlled electric light source. A hinged top cover serves to keep the materials in close contact and to reduce or eliminate stray light into the darkroom.
The contact printer is used to expose the negative's image onto the paper for a few seconds, creating an invisible latent image in the paper. The operator may use a manual switch and count off the seconds or may control an electric timer switch.
With the black and white gelatin-silver process this may be done using a red "safelight" for darkroom illumination. The contact printer may also contain a safelight so that the negative may be examined before the photographic paper is laid upon it.
After exposure, the exposed paper is processed using chemicals to produce the final print.
Since this process produces neither enlargement nor reduction, the paper print is exactly the size of the negative. Contact prints are used to produce proof sheets from 35mm negative (from 135 film cassettes) to aid in the selection of images for further enlargement. Using 120 roll film, once a common negative size for popular cameras, contact prints are often used to produce the final print size. In medium and large format photography, contact prints are prized for their extreme fidelity to the negative, with exquisite detail that may be seen with the use of a magnifying glass. A disadvantage of contact prints for fine arts use is the inability to modify the exposure selectively on the print (see the enlarger article).
Contact printing was also used at one time in photolithography and in printed circuit manufacturing.