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To promote their brand, entrepreneurs need hundreds and thousands of flyers, brochures and other promotional materials. Digital printers cannot be used for producing print outs in bulk because they have limited printing capacity, and the wear and tear is also more. Furthermore, the quality of the prints is also not up to the mark. This is where litho printers become indispensable. These devices have the capability to consistently produce thousands of high-quality print outs. Apart from being durable and resilient, they are cost-effective too. The working of litho printing is unique, but intricate. The printing process begins with the preparation of the plate, which is coated with a photosensitive emulsion. There are basically two ways to transfer the image to be printed on to the plate. In the first method, a film is placed on the top of the plate and it is exposed to light. In the second method, a machine uses lasers to expose the plate. In either case, a photographic negative of the image to be printed is generated. Thereafter, the emulsion is released and the positive image is transferred on to it. The emulsion is treated with chemicals to remove the un-exposed portions. Once the plate has been made, the printable image is made water-repelling and the non-printing regions are rendered water-attracting. The plate is then mounted on a rotating plate cylinder. While rotating the plate first comes in contact with water that adheres to the negative portions of the image. Later on, it comes in contact with ink that sticks on the positive portions of the image. If the image has to be transferred directly to the paper, then a cylinder with rubber surface is rolled over the plate. This rubber surface performs two printing functions; firstly, it removes all the excess water, and secondly, it picks up the ink. When this cylinder is pressed over the paper, the printable image gets transferred on to it. Thus, the working of litho printers is certainly complicated. However, the plate formed is quite durable and can be used over and over again. Due to this factor, the cost of printing is dramatically reduced. These features make litho printers highly suitable for commercial printing.
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