offsetti

Offsetti, or offset printing, is a widely used printing method based on lithography in which the image to be printed is first transferred from a flat plate to a rubber blanket, and then to the printing surface. The technique relies on the differential affinity of oil-based inks and water: the image areas accept ink while the non-image areas are kept dampened to repel ink.

Process and equipment

In a typical offset press, the plate cylinder holds the image, which is transferred to a blanket cylinder and then pressed onto the substrate. A dampening system applies water to keep non-image areas ink-free, while a separate inking system supplies the ink. Modern presses may use computer-to-plate (CTP) prepress workflows and can employ waterless or alcohol-reduced dampening systems. Substrates include various grades of paper and light cardboard, with applications ranging from magazines and catalogs to packaging.

Types and variants

Offsetti encompasses sheet-fed offset, used for books, magazines, and small runs, and web offset, which feeds paper from rolls for high-volume production. Within web offset, coldset printing is common for newspapers, while heatset printing is used for high-quality magazine and catalog production on coated stock. Digital and hybrid approaches have further integrated offset with digital workflows and faster make-ready.

Advantages and limitations

Offsetti delivers high print quality, consistent color, and cost efficiency for large runs, along with versatility across substrates. However, it requires substantial makeready and is less economical for very short runs. Environmental considerations include ink and solvent use, though modern practices emphasize lower emissions, recycling, and advances in inks and dampening solutions.

Usage

Today, offsetti remains a dominant method in commercial printing, newspapers, magazines, catalogs, and packaging worldwide.