CMYK color model of the primaries: cyan and yellow produce green, cyan and magenta produce blue, yellow and magenta produce red (these subtractive secondary colors correspond roughly to the additive primary colors), plus layering all three of them resulting in black. With halftoning, a full continuous range of colors can be produced. To improve print quality and reduce moiré patterns, the screen for each color is set at a different angle. While the angles depend on how many colors are used and the preference of the press operator, typical CMYK process printing uses any of the following screen angles: The "black" generated by
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