planografische

Planography, or planographic printing, is a class of printmaking in which the printing surface is flat. In planographic processes, the image and non-image areas lie on the same plane. Ink is applied to the surface and adheres to image areas while non-image areas are kept receptive to water or dampening solutions, which repel the ink.

It originated with lithography, invented by Alois Senefelder in the late 18th century in Munich, as a method to reproduce drawings. It relied on the ink-repellent properties of water on a greasy image. Early lithography used a smooth limestone stone; modern practice uses metal plates and synthetic substrates.

Today the most widespread form is offset lithography, a planographic process in which the image is first transferred ("offset") to a rubber blanket and then to paper, enabling high-speed production and compatibility with diverse substrates. The process relies on the hydrophobic image areas and hydrophilic non-image areas.

Planographic printing is valued for its ability to render a wide tonal range and fine details, making it common in art reproductions, commercial printing, newspapers, and packaging. It is contrasted with relief printing (raised surfaces), intaglio (incised surfaces), and screen printing (stencil-based).

Contemporary planographic practice includes computer-to-plate workflows, alcohol- and water-based dampening systems, and various coatings that optimize ink transfer and printing efficiency.