printing press is a device for applying pressure to an inked surface resting upon a print medium (such as paper or cloth), thereby transferring the ink. It marked a dramatic improvement on earlier printing methods in which the cloth, paper or other medium was brushed or rubbed repeatedly to achieve the transfer of ink, and accelerated the process. Typically used for texts, the invention and global spread of the printing press was one of the most influential events in the second millennium.

Johannes Gutenberg, a goldsmith by profession, developed, circa 1439, a printing system by adapting existing technologies to printing purposes, as well as making inventions of his own. Printing in East Asia had been prevalent since the Tang dynasty, and in Europe, woodblock printing based on existing screw presses was common by the 14th century. Gutenberg's most important innovation was the development of hand-molded metal printing matrices, thus producing a movable type based printing press system. His newly devised hand mould made possible the precise and rapid creation of metal movable type in large quantities. Movable type had been hitherto unknown in Europe. In Europe, the two inventions, the hand mould and the printing press, together drastically reduced the cost of printing books and other documents, particularly in short print runs.

The printing press spread within several decades to over two hundred cities in a dozen European countries. By 1500, printing presses in operation throughout Western Europe had already produced more than twenty million volumes. In the 16th century, with presses spreading further afield, their output rose tenfold to an estimated 150 to 200 million copies. The operation of a press became synonymous with the enterprise of printing, and lent its name to a new medium of expression and communication, "the press".

In Renaissance Europe, the arrival of mechanical movable type printing introduced the era of mass communication, which permanently altered the structure of society. The relatively unrestricted circulation of information and (revolutionary) ideas transcended borders, captured the masses in the Reformation and threatened the power of political and religious authorities. The sharp increase in literacybroke the monopoly of the literate elite on education and learning and bolstered the emerging middle class. Across Europe, the increasing cultural self-awareness of its peoples led to the rise of proto-nationalism, and accelerated by the development of European vernacular languages, to the detriment of Latin's status as lingua franca. In the 19th century, the replacement of the hand-operated Gutenberg-style press by steam-powered rotary presses allowed printing on an industrial scale.

Etching is traditionally the process of using strong acid or mordant to cut into the unprotected parts of a metal surface to create a design in intaglio(incised) in the metal. In modern manufacturing, other chemicals may be used on other types of material. As a method of printmaking, it is, along with engraving, the most important technique for old master prints, and remains in wide use today. In a number of modern variants such as micro-fabrication etching and photo-chemical milling it is a crucial technique in much modern technology, including circuit boards.

In traditional pure etching, a metal (usually copper, zinc or steel) plate is covered with a waxy ground which is resistant to acid. The artist then scratches off the ground with a pointed etching needle where he or she wants a line to appear in the finished piece, so exposing the bare metal. The échoppe, a tool with a slanted oval section, is also used for "swelling" lines. The plate is then dipped in a bath of acid, technically called the mordant (French for "biting") or etchant, or has acid washed over it. The acid "bites" into the metal (it dissolves part of the metal) where it is exposed, leaving behind lines sunk into the plate. The remaining ground is then cleaned off the plate. The plate is inked all over, and then the ink wiped off the surface, leaving only the ink in the etched lines.

The plate is then put through a high-pressure printing press together with a sheet of paper (often moistened to soften it). The paper picks up the ink from the etched lines, making a print. The process can be repeated many times; typically several hundred impressions (copies) could be printed before the plate shows much sign of wear. The work on the plate can also be added to by repeating the whole process; this creates an etching which exists in more than one state.

Etching has often been combined with other intaglio techniques such as engraving (e.g., Rembrandt) or aquatint (e.g., Francisco Goya).

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