Photo-quality printing in photo quality printing is saved in a CMYK file format to best utilize either the commercial printing process or inkjet printing photo quality output capabilities. CMYK dots of Cyan (blue), Magenta (red), Yellow, and Black are placed next to each other in specific patterns that trick the eye into seeing millions of colors. Photo quality inkjet printing transfers 4 or more toner colors to the substrate in a single cycle through the printer. In photo quality commercial printing each color of ink is applied separately. The high resolution photos are printed (or output) at a line screen value of
Secondary color secondary CMY colors (with secondary colors in boldface) are: Ideally, combining three perfect primary colors in equal amounts would produce black, but this is impossible to achieve in practice. Therefore a "key" pigment, usually black, is added to printing to produce dark shades more efficiently. This combination is referred to as CMYK, where K stands for Key. Before the discovery of CMY, at least as far back as Goethe, the best primary colors were thought to be red, yellow, and blue. Mixing these pigments in equal amounts produces orange, green, and purple: That is, the primary and secondary RYB colors