Color printing yellow (minus-blue) overprinted by magenta (minus green) yields red. Where all three inks may overlap, almost all incident light is absorbed or subtracted, yielding near black, but in practical terms it is better and cheaper to use a separate black ink instead of combining three colored inks. The secondary or subtractive colors cyan, magenta and yellow may be considered "primary" by printers and watercolorists (whose basic inks and paints are transparent). Two graphic techniques are required to prepare images for four-color printing. In the "pre-press" stage, original images are translated into forms that can be used on a printing press,
Combination printing the common belief that photography is a simply mechanical, straightforward process with no creative elements. Combination printing remained a great way of working with changing images to add that creativity. Combination printing Combination printing is the photographic technique of using the negatives of two or more images in conjunction with one another to create a single image. Similar to dual-negative landscape photography, combination printing was technically much more complex. The concept of combination printing stemmed from the desire to create more of a fine art within photography and often more idealized images. Combination printing was popular in the mid-19th century