Among the available printing technologies, there is no other that can compare with sheetfed offset printing in terms of flexibility with regard to: the printing materials used, the print run size, the finishing possibilities or the range of products that can be produced with it.
What is offset printing?
Offset printing is referred to in technical terminology as intermediate printing. This is primarily due to the specifications of this printing method. This is because the graphic design is transferred onto printing plates covered with photosensitive emulsion on an aluminium substrate. The moulds are prepared using CtP (Computer to Plate) technology. The finished moulds are mounted (fixed) on mould cylinders. In contact with the ink and water rollers, an ink layer with a wetting solution is applied to the printing elements of the mould. This image is then transferred from the mould cylinder via physical contact to an intermediate cylinder covered with a rubber jacket. From the intermediate cylinder, the image is transferred directly to the printing (impression) cylinder underneath and to the printed sheet of paper currently on the surface of this cylinder. This is the operating diagram of a single printing unit (so-called printing unit). Between the printing units, the sheets are transferred by means of transfer cylinders (so-called transferters) with the use of special feet on their edges, which transfer the sheets to each other in a very precise (relay-like) manner.
Four process colours are required to print a full-colour image on a sheet: Cyan – the colour blue (C), Magenta – the colour purple (M), Yellow – the colour yellow (Y), Black – the colour black (K), in short: CMYK. For each process colour, one print mould is required, installed on individual print units.