Every dot of colour, on every printed page, has to be carefully worked out as part of the printing process. High volume print runs, such as glossy magazines, are reproduced with rotogravure. This process is capable of printing 14m of paper every second.
The print cylinders are engraved with precise cells, making this an intaglio process. During printing, the ink is collected in these cells and from there it is deposited onto the paper. A cylinder is required for each of the four colours, plus any spot colour - see luminous yellow. Afterwards, the cylinders are re-polished, so they can be used all over again.