How do individual printing technologies differ and why is it important to know the four basic printing colours?
Colours in Printing
During printing, coloured image reflects colour – this is the CMYK model, colour model based on subtractive colour mixing. By mixing, colours subtract themselves and this way, the colour spectrum that is reflecting from the surface is limited. CMYK is used mainly in reproduction devices that create colours using pigment mixing. The model is build on the combination of four colours out of which all other colour combinations are made [azure (Cyan), purplish (Magenta), yellow (Yellow) and black (blacK)].
By using the CMYK, that is, by mixing of elementary colours, some colours cannot be printed and in that case, printing with direct colours is used. These are supplied directly by manufacturers or mixed in the printing house according to the Pantone sampler. Usually, it happens with printing of bright colours, silver, gold etc. When using the offset technology, the base is divided into four elementary colours. For each colour, separate printing form is made. During printing, the colours are printed separately (gradually over each other and in that way, the reproduced image will form itself into a required shape).