Photo-offset printing, also known as offset lithography, is a printing technique that uses plates and the principle of water and oil repulsion to produce high-quality prints. There are various synonyms for photo-offset printing, such as litho printing, offset printing, lithography, and planographic printing. The term "planographic printing" denotes printing from a flat surface, while "litho printing" and "lithography" are derived from the Greek word "lithos," which means stone. These terms were originally used because the process was often performed on a flat stone surface. Offset printing is popularly used for a range of products, from newspapers and magazines to brochures, posters, and packaging materials.