Gum bichromate negatives of cyan, magenta, and yellow or red, green, and blue are used for a full-color image. Some photographers prefer substituting the cyan emulsion in the CMYK separations with a cyanotype layer. A simple duotone separation combining orange watercolor pigment and a cyanotype can yield surprisingly beautiful results. Low density photographic negatives of the same size as the final image are used for exposing the print. No enlarger is used, but instead, a contact printing frame or vacuum exposure frame is used with an ultraviolet light source such as a mercury vapor lamp, a common fluorescent black light, or the
Combination printing would be able to combine the two negatives by blending them together. Photographers such as William Frederick Lake Price and Oscar Rejlander are famous for using combination printing. Starting as early as the mid-19th century, new methods such as the combination printing, began to change the way people looked at different photographic techniques. Controversy broke out in the photographic community about the use of combination printing. Photographs originally had been regarded as truth and it was perceived that the camera never lied. However, with the newfound ability to manipulate the final product, the notion that photographs depicted "truth" was soon