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Offset printing is a common printing technique in which the inked image is transferred (or "offset") from a plate to a rubber blanket and then to the printing surface. When used in combination with the lithographic process, which is based on the repulsion of oil and water, the offset technique employs a flat (planographic) image carrier.
Waterless printing is an offset lithographic printing process that eliminates the use of water or the dampening system used in conventional printing. [1] Unlike traditional printing presses, waterless offset presses do not use a dampening solution to clear the press of ink. [2] Proponents of the technology claim efficiency and ecological ...
In the offset lithography process, the mechanicals would be photographed with a stat camera to create a same-size film negative for each printing plate required. Paste up relied on phototypesetting , a process that would generate "cold type" on photographic paper that usually took the form of long columns of text.
The paper passes between the blanket cylinder and a counter-pressure or impression cylinder and the image is transferred to the paper. Because the image is first transferred, or offset to the rubber blanket cylinder, this reproduction method is known as offset lithography or offset printing. [13]
The plates, called stereotypes, are coated with ink, then pressed against a continuous roll of paper. Rotary letterpress printing was used in the mid-twentieth century to print most major newspapers. In offset lithography, the image is chemically applied to a plate, generally through exposure of photosensitive layers on the plate material.
Different paper types have different ink absorption rates; uncoated papers can absorb more ink than coated ones, and thus can show more gain. As printing pressure can squeeze the ink out of its dot shape causing gain, ink viscosity is a contributing factor with coated papers; higher viscosity inks can resist the pressure better. Halftone dots ...
The collotype printing process was used for volume mechanical printing before the introduction of simpler and cheaper offset lithography. It can produce results difficult to distinguish from metal-based photographic prints because of its microscopically fine reticulations which compose the image. Many old postcards are collotypes.
Offset ink is a specific type of ink used in conjunction with offset printing presses, such as those used to produce letterpress or lithography prints. Such ink must be specially formulated to resist other chemicals it will come in contact with on the printing press.