Lithography

Lithography is a planographic printing technique in which the image is created without raised or recessed areas on the printing surface. Both the printing and non-printing areas are located on the same level, and the image is formed through differences in the surface’s ability to accept grease and water.

The name lithography comes from the Greek words lithos (stone) and graphein (to write or draw), meaning “stone writing”. The term refers to the original form of the technique, in which a limestone was used as the printing surface. When the image is actually printed from a stone, the terms stone printing or stencil? are sometimes used? (Note: in English, the established term is simply “stone lithography” or “lithographic printing from stone”.) Lithography from a metal plate is based on the same principle but is usually referred to as metal plate lithography or simply lithography.

Lithography was developed by the German playwright and inventor Alois Senefelder in 1797/98. Senefelder was looking for an inexpensive method for reproducing his own theatrical manuscripts and musical scores. Through his experiments, he discovered that the difference between grease-treated and water-receptive areas on a flat surface could be used to control where printing ink adhered. This made it possible to develop a new printing process in which an image could be transferred from a flat printing surface without the need to cut, engrave, or build up the image as a relief structure. This discovery laid the foundation for lithography, a graphic method in which chemical properties of the surface replaced the mechanical differences between raised and recessed printing areas that characterised earlier printing techniques.

The technique became highly significant in artistic printmaking, illustration, map production, and commercial printing. It allowed artists and printers to work directly on the printing surface with a freedom that differed from earlier relief and intaglio techniques.

A lithographic printing surface consists of a flat area treated so that certain parts accept grease-based printing ink, while other areas retain water and repel the ink.

The image is drawn or transferred using a grease-based material, such as lithographic crayon, tusche, or other greasy media. After chemical treatment, the drawn areas become receptive to printing ink, while the remaining surface retains water.

During printing, the plate is first dampened with water. The water remains on the areas that should not print. When grease-based printing ink is rolled across the surface, it adheres only to the grease-treated parts of the image.

The paper is then pressed against the printing surface, and the ink is transferred to the sheet. Unlike intaglio and relief printing, the image is therefore not created through a physical structure in the printing plate, but through chemical differences in the properties of the surface.

The original form of lithography is stone lithography, where the printing surface consists of a limestone block. Traditionally, dense, fine-grained limestones were used, particularly those from Solnhofen in Bavaria, as they provide an even surface suitable for detailed work.

The stone is first prepared so that the surface obtains the correct texture and can receive the drawing. The artist or printer then works directly on the stone using grease-based materials. After chemical processing, the stone functions as a lithographic printing surface.

Stone lithography has several technical characteristics:

• The stone provides an extremely even working surface capable of reproducing fine lines and subtle tonal variations.
• The image can be built up through drawing, flat areas, brushwork, and tonal transitions.
• The printing surface can be used for multiple impressions and then ground down for reuse.

In colour lithography, several stones are usually used, with each stone representing one colour or one colour layer. Accurate registration between the stones is essential in order for the colours to build up the final image.

Although lithography was originally developed using limestone as the printing surface, metal plates were later introduced as an alternative. Aluminium became particularly important, but other metals have also been used.

Metal plate lithography is based on the same fundamental principle as stone lithography: the image and the non-printing areas are located on the same level, and the image is created through differences in how the surface reacts to water and grease. The printing plate is treated so that the areas intended to reproduce the image accept grease-based printing ink, while the remaining areas retain water and repel the ink.

The transition from stone to metal plates provided several practical advantages. Limestone is heavy and difficult to handle, especially in larger formats. Metal plates are much lighter, more durable, and can be produced with consistent quality. They can also be bent and mounted around cylindrical rollers, making them suitable for use in rotary printing presses.

The ability to mount metal plates on rollers was crucial for the development of modern high-speed printing machines. Instead of moving a flat printing surface back and forth against the paper, a rotating cylinder can carry the printing plate continuously through the press. This makes very high printing speeds and efficient mass production possible.

This development was an important prerequisite for the transition from traditional stone lithography to industrial lithography and later offset printing. At the same time, metal plate lithography remained an independent artistic technique, as it provides many of the same artistic possibilities as stone lithography while offering different practical advantages.

Offset is based on the same fundamental principle as lithography, but the image is not transferred directly from the printing plate to the paper.

The technique was originally developed to solve the problem of printing on materials that were unsuitable for direct printing from a hard printing surface. This was particularly relevant when printing on metal sheets and other rigid materials, where it was difficult to achieve even contact between the printing surface and the material.

The solution was to use an elastic rubber blanket as an intermediate transfer surface. The image is first transferred from the printing plate to the rubber blanket, and then from the blanket to the material being printed.

It was later discovered that this method also produced excellent results on paper. Offset therefore developed into the dominant industrial method for producing newspapers, books, magazines, and other printed materials.

A technical difference between direct lithography and offset concerns how the reversal of the image occurs:

• In direct lithographic printing, the image is mirrored on the printing surface so that it appears correctly oriented on the paper.
• In offset printing, the image is first transferred to the rubber blanket and then transferred again to the paper. This additional transfer creates a second reversal, meaning that the final print is correctly oriented in relation to the image on the printing plate.

Although offset is not usually referred to as lithography in everyday usage, the technique is still based on the same lithographic principles developed by Senefelder.

Colour lithography is based on the same principle as black-and-white lithography but requires several printing surfaces. Each stone or metal plate is normally used for one colour or one colour layer.

The colours are printed one after another with precise registration. By combining transparent layers of colour, a wide range of colours and tonal variations can be achieved.

Historically, colour lithography became particularly important for posters, illustrations, and image reproduction before photographic and digital methods replaced many of these functions.

Lithography continues to be used as an artistic technique, while its principles are also carried forward into modern production technology.

Digital workflows can be incorporated into the production of lithographic printing surfaces, for example through the creation of films, light-sensitive plates, or digital working files used as the basis for a physical printing surface.

The use of modern technology does not necessarily change the graphic character of the work. If the artist develops the printing surface and the printing process as part of the creative process, the result can still be considered original printmaking.

Lithography therefore represents a meeting point between chemistry, material knowledge, and graphic craftsmanship – from the first stone prints of the late 18th century to today’s combination of traditional methods and modern technology.