to determine 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 can be seen with the use of a magnifying glass. A disadvantage to using contact prints in the fine-arts is the laboriousness of modifying exposure selectively, when the use of an enlarger can achieve the same purpose. Because light does not pass any significant distance through the air or through lenses in going from the negative to the print, the contact process ideally preserves all the detail that is present in the negative. However, the exposure value (EV) range, the variation from darkest to lightest regions, is inherently greater in negatives than in prints. Finished prints When large format film is contact printed to create finished work, it is possible, but not easy, to use local controls to interpret the image on the negative. "Burning" and "dodging" (either increasing the amount of light that one area of the print receives, or decreasing the amount of light in order to achieve the ideal tonal range in a particular area) require painstaking work with photographic masks, or the use of a production contact printing machine (Arkay, Morse, Burke and James are manufacturers who make contact printing machines). Some alternative processes or non-silver processes, such as van Dyke and cyanotype printing, must be contact printed. Medium or large format negatives are almost always used for these types of printing. Images from smaller formats may be transferred to a larger format negative for this purpose. Production tools Contact printing machines are more elaborate devices than the more familiar and widely available contact printing frames. They typically combine in a box the light source, intermediate glass stages, and a final glass stage for the negative and paper to be placed upon, as well as an elastic pressure plate to keep the negative and the paper in tight contact. Dodging can be accomplished by placing fine tissue paper on the intermediate glass stages between the light source and the negative/paper sandwich to modify the exposure locally. The benefit to such time intensive techniques is the ability to then make multiple prints with negligible variation, at full production speed. Other uses for the technique Contact printing was also once used in photolithography, and in printed circuit manufacturing. Motion picture prints are often contact printed either from an original, or a