same orange base as color C-41 films; the base on XP2 is Purple and Fuji films are clear. The orange base on the Kodak film allows them to be printed with correct blacks on standard color printing machines, but this film can be difficult to print on multigrade black-and-white paper, whose contrast is determined by the use of a colored filter during the printing process. Conversely, the clear-based Ilford and Fuji films sometimes results in off-color prints on color paper, but can be optically printed on black-and-white paper, just like any other black-and-white film. It is often said that prints from these films do not have grain. While they may not appear to have grain, this statement is technically incorrect. On an image from regular black-and-white film, the individual silver particles forming the image are seen as grain. The image on the C-41 films, however, does not contain silver. Instead, C-41 negatives and prints have clouds of dye, causing the resulting image to appear different from that of silver grain. Traditional black-and-white films While regular black-and-white films are not intended for use with C-41 chemistry, some photographers have used C-41 developer to develop high-contrast black-and-white films (such as traffic surveillance film and Kodak's Technical Pan). This is done in order to lower the contrast. In this application, only a silver image is formed; the bleach step of the C-41 process is not used, as it would destroy the image. Cross processing It is also possible to cross-process slide film for the E-6 process in C-41, which yields negatives with a color shift and stronger saturation. (C-41 film also may be processed in E-6 yielding positive images with a strong green cast, caused by the orange mask.) Varying brands and film speeds yield different color shifts producing bright, saturated colors and high contrast. C-41 film can be processed in standard black-and-white chemicals, to produce a monochrome negative image. The negatives will typically be of very low contrast, and cloudy, partly caused by the orange mask. See also Chromogenic Replenishment (photography) References External links Kodak process C-41 (color negative) processing manual Z-131 (PDF) Photographic film processes