What is "lithography"

Lithography \Li*thog"ra*phy\, n. [Cf. F. lithographie.]

1. The art or process of putting designs or writing, with a greasy material, on stone, and of producing printed impressions therefrom. The process depends, in the main, upon the antipathy between grease and water, which prevents a printing ink containing oil from adhering to wetted parts of the stone not covered by the design. See Lithographic limestone, under Lithographic.

2. a printing process for reproducing images, using any flat surface, such as a metal plate, in a manner similar to lithography[1].

3. The process of producing patterns on semiconductor crystals by exposing photosensitive coatings on a matrix, such as silicon, to light patterns in the form desired for the circuit, and subsequently treating (e.g., chemically) the patterns thus formed in such a way as to create integrated semiconductor circuits with the desired properties. This is the principle method (1990's) to create the high-density integrated circuits used in the digital computers on which you are reading this.

1813, from German Lithographie (c.1804), coined from Greek lithos "stone" (see litho-) + graphein "to write" (see -graphy). The original printing surfaces were of stone. Process invented 1796 by Alois Senefelder of Munich (1771-1833). Hence, lithograph "a lithographic print," a back-formation first attested 1828. Earlier senses, now obsolete, were "description of stones or rocks" (1708) and "art of engraving on precious stones" (1730).

n. The process of printing a lithograph on a hard, flat surface; originally the printing surface was a flat piece of stone that was etched with acid to form a surface that would selectively transfer ink to the paper; the stone has now been replaced, in general, with a metal plate.

1. n. a method of planographic printing from a metal or stone surface

2. the act of making a lithographic print

Lithography is a method of printing originally based on the immiscibility of oil and water. The printing is from a stone ( lithographic limestone) or a metal plate with a smooth surface. It was invented in 1796 by German author and actor Alois Senefelder as a cheap method of publishing theatrical works. Lithography can be used to print text or artwork onto paper or other suitable material.

Lithography originally used an image drawn with oil, fat, or wax onto the surface of a smooth, level lithographic limestone plate. The stone was treated with a mixture of acid and gum arabic, etching the portions of the stone that were not protected by the grease-based image. When the stone was subsequently moistened, these etched areas retained water; an oil-based ink could then be applied and would be repelled by the water, sticking only to the original drawing. The ink would finally be transferred to a blank paper sheet, producing a printed page. This traditional technique is still used in some fine art printmaking applications.

In modern lithography, the image is made of a polymer coating applied to a flexible aluminum plate. The image can be printed directly from the plate (the orientation of the image is reversed), or it can be offset, by transferring the image onto a flexible sheet (rubber) for printing and publication.

As a printing technology, lithography is different from intaglio printing (gravure), wherein a plate is either engraved, etched, or stippled to score cavities to contain the printing ink; and woodblock printing or letterpress printing, wherein ink is applied to the raised surfaces of letters or images. Today, most types of high-volume books and magazines, especially when illustrated in colour, are printed with offset lithography, which has become the most common form of printing technology since the 1960s.

The related term "photolithography" refers to when photographic images are used in lithographic printing, whether these images are printed directly from a stone or from a metal plate, as in offset printing. In fact, "photolithography" is used synonymously with "offset printing". The technique as well as the term were introduced in Europe in the 1850s. Beginning in the 1960s, photolithography has played an important role in the fabrication and mass production of integrated circuits in the microelectronics industry.