In industrial printing processes, e.g. offset printing, gravure and flexo printing, only one colour can be printed with each printing form in the printing press. To obtain a multicoloured motif, the printing substrate has to be printed several times successively. Printing templates therefore have to be analysed into separate single colour images, so-called colour separations. Usually the print templates are divided into the four colours of the CMYK system for this purpose. Each colour separation only shows the individual parts of a printing colour in the entire image. Furthermore, if special colours are used, further colour separations have to be created. The following always applies: a colour separation exists per printing colour. When printed over each other, all colour separations again have to give the motif of the printing template. Colour separations are produced today on the computer with the help of corresponding software solutions. The analogue use of special colour filters is no longer necessary.