The term 'multicolor' comprises all technologies and processes that produce print results in a quality superior to that of conventional four-color printing. These include:
•printing with five, six or seven process colors
•the use of spot colors
•the use of GCR reproduction
•the use of special screening methods
•the use of high-quality printing materials
•surface treatment of the printed products
Multicolor opens up a market segment to repro users that is characterized by high quality, high color fidelity and enhanced color gamut. Seven-color printing expands the color space by special ink sets with purer and more chromatic colors: in addition to cyan, magenta and yellow, the red, green and blue inks are also changed.
As a result, it is possible to match real colors more closely. Consequently, reproductions with a greater color intensity are possible. These points are interesting for art reproduction and for printing calendars, posters or high-quality brochures.
Special techniques for separation such as GCR reproduction produce more stable neutral tones as these are generated with black ink only. In addition to enhanced shadow definition, there is also less color drift and wet-on-wet problems with this technology.
Frequency-modulated screening suppresses moirés and the formation of rosettes, thus producing a photo-realistic quality in printing. This method is especially suited to printing with more than four inks.
Multicolor is used to refer to printing processes where the color space is extended by additional chromatic process colors. In this process, separation of image data and graphics is not only with the normal process colors (cyan, magenta, yellow and black) but also with additional chromatic process colors (HiFi Color, Hexachrome, five, six or seven-color printing).
By contrast, all processes where any number of single spot colors are used are not referred to as multicolor. In this case, there is no separation of image data and/or graphics with the additional colors.
It is also not a multicolor process if one of the process colors is replaced by a spot color (e.g. magenta by red) in conventional four-color printing.
Multicolor profiles are especially suited for the use of classic screening methods. Each color is reproduced by a maximum of four optimal colors. This minimizes the risk of moiré. The use of amplitude-modulated screening is possible. The screen angles for the additional colors are selected so that the angle of the complementary color is used, for example:
•Orange with the screen angle of cyan, its complementary color
•Green with the screen angle of magenta, its complementary color
•The formation of moiré, however, must be expected if blue is used with the screen angle of its complementary color (yellow). For that reason, it's better to use the angle of magenta or black.