Offset printing a core competence for Stora Enso
An absolute majority of our products are printed in offset – newspapers, magazines, books, catalogues, sales promotion, direct mail, and all kinds of packages – just to name a few. A deep understanding of what the offset printing process demands of the paper is therefore essential for a successful relation with our business partners in printing, publishing, and packaging.
Lithographic offset printing has developed immensely since Senefelder’s invention of the process more than 200 years ago. Today, we have three distinct offset processes that are extensively used to print different products. In coldset offset, used in newspaper production, the liquid phase of the ink is absorbed by the paper, leaving a relatively weakly bound pigment film on the paper surface. This is why we sometimes have dirty fingers after reading our morning paper. Sheetfed offset is mainly used for short-series printing of high-quality products such as sales promotion material and coffee-table books. These products are printed on heavy coated paper with a paste ink that gives a smooth and glossy, well-bonded ink film on the paper surface.
Heat-set web offset (HSWO) is used to print products such as weekly or monthly magazines, often on a relatively thin coated paper. Here, the ink is dried by passing the printed web through a drying oven where some solvents are removed, leaving a solid ink film on the paper surface.