RGB and CMY Colour Sectors

R red
G green
B blue

Additive ink mixing
(source-generated light)
Use: Screens, monitors, projectors, scanners

C cyan
M magenta
Y yellow

SUBTRACTIVE ink mixing
(light is partially absorbed and partially deflected by the backplate)
Use: Printers

Transparent Inks

During printing, black ink (K) is added to the CMY model. This leads to the CMYK ink model.

It features multiple names in the area of printing: CMYK, four-colour print, stabilization, process inks, transparent inks. All the names mean the same – the reproduced image is divided into a set of four basic colours: Cyan, magenta, yellow, and black.

The individual colours are gradually printed over one another. Eventually, all the colours of the reproduced image are created.

Direct Inks

Offset print may be based on direct inks. Direct inks are specially mixed printing inks used instead of transparent inks (CMYK) or in combination with them.

Direct inks are used in those applications which do not produce the required colour shades through the combined use of transparent inks. Direct inks may also be used for various effects – metallic colours, reflective colours, light pastel colours, etc.

Direct colours are specified per the manufacturers’ samplers (e.g.  Pantone, HKS).

Direct colour printing features greater quality; however, it is costlier than transparent ink printing. Every direct colour must have its own printing plate in the press machine.