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The lithography for printing and non-printing elements on the same level. More sophisticated printing zone, the fact that they are ink-accepting, areas where no printing plate ink-repellent. physical inter-face surface phenomena created by this effect.
lithography easily be divided into:
– Stone lithography (using direct printing technique stone plates)
– Collotype (direct printing method)
– Offset printing (indirect printing process), and
– Di-litho (offset printing plates for direct printing process).
lithograph was created by Alois Senefelder in 1796 took the stone image to be printed using a special ink. Moisten the stone was before or after that displays the non-image did not take the stone surface of the ink.
Collotype is actually a lithography technology. The light-sensitive gelatin is exposed to levels above a glass base on the negative and then developed. Locations are relative to different swelling properties of water produced. After the printing plate dampened differentiated shades absorption characteristics are formed. As well as stone lithography, collotype only usable art goods (and a very short print runs).
leading lithographic offset printing technology. This is an indirect lithography technology, in a situation where the ink is first transferred to the printing plate an adaptive midpoint carrier – the blanket – and subsequently to the substrate.
To a paint water-repellent effect of the plate (the typical interaction of platen surface and ink), two widely used techniques:
– Conventional offset technology: wetting the printing plate using dampening solution ( water with additives). A humidifier is a disc damping by a very beautiful film rolls. The non-image display at the hydrophobic sheet which is accepting oleophilic water-receptive and ink surfaces, only about 100% unreceptive water. The film of wetting inhibits the transfer of ink. Since this technology is by far the most widely used is essentially the hideous results from the ink and dampening regularly is always associated with “offset printing.” For this reason, inking and dampening required “offset printing.”
-Waterless offset technology mainly on the plate surface ink-repellent, for example, the corresponding layer of silicone. The ink-receptive base region is exposed to a deliberate interruption of a silicone layer (thickness of only about 2 microns). This treatment is called “waterless offset” (often a “dry offset”). Suitable for special inks and printing plates to be used for both of these techniques.
The di-litho technology, lithography technology that prints directly to the printing plate to the substrate, even specifically developed for newspaper printing. The benefit of this technology to the traditional high pressure rotary printing machines could be used. The printing presses, these units have been modified by installation of damper units. Printing was performed conventional printing plates, but a special coating was applied to them because very high stress due to direct contact with the paper and the high degree of stability was essential for journal printing the entire print run. This technology can only be played in a short time. When new investment journal printing companies, this kind of technology is replaced by a rotary offset printing presses, which print over the substrate blanket cylinder.
advantage offset lithography
– consistently high image quality.
– much faster and easier production of plates.
– extended life of discs, because they only come in contact with the printing blanket, which happens to be softer and less abrasive than the paper
– The most inexpensive production of high-quality images in large quantities.
Disadvantages
– the high cost of a small amount of
– The picture quality is excellent for commercial purposes but not as good as the rotogravure printing or screen printing.
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Source by Saso Gjorevski