Offset printing is a traditional printing method that uses a printing press to transfer ink from a plate to a rubber blanket and then onto paper or other materials. The process is called "offset" because the ink is not transferred directly from the plate to the paper, but is instead offset or transferred from the plate to the blanket and then onto the paper.

The process of offset printing begins with the creation of printing plates. These plates are made from metal or plastic and are coated with a photosensitive emulsion. The design or image to be printed is then projected onto the plate, which is then exposed to light. The areas of the plate that are exposed to light harden, while the areas that are shielded from light remain soft. The plate is then washed with water, which removes the soft, unexposed areas of the emulsion, leaving the image on the plate.

Once the plates are ready, they are mounted on the printing press. The press uses a series of rollers to transfer ink from the plate to a rubber blanket, which then transfers the ink to the paper or other materials. The ink is transferred to the blanket by way of a series of rollers that are inked and then pressed against the plate. The ink is then transferred to the blanket, which is pressed against the paper or other materials, transferring the image.

Offset printing is known for its high-quality and consistency, making it suitable for a wide range of printing applications, including printing of books, brochures, posters, newspapers, and packaging. It is also a cost-effective option for printing large quantities, as the plates and press setup can be used multiple times before needing to be replaced.