Lusid Motif GDES250_TheFinalSubmission_McCarthy_Andrew_W2018_j | Page 20

Modern printing methods such as laser and ink- jet printing are known as digital printing. Digital printing consists of an image being sent directly to the printer using digital files such as PDFs and those from graphics software such as Illustrator and InDesign. This eliminates the need for printing plates, commonly used in offset printing, which can save money and time. Prepress Plating Decisions Other Plate Types A print job that prints only in black ink requires only one plate. A print job that prints in red and black ink requires two plates. In general, the more plates that are needed to print a job, the higher the price. In screen printing, the screen is the equivalent of the printing plate. It can be created manually or photochemically and is usually a porous fabric or stainless steel mesh stretched over a frame. Offset Printing Process In some cases, there may be more than four plates — if a logo must appear in a certain Pantone color, for example, or if a metallic ink is used in addition to full-color images. Things become more complicated when color photos are involved. Offset printing requires the While offset printing still often results in slightly separation of colored images into four ink colors better quality prints, digital methods are being — cyan, magenta, yellow and black. The CMYK worked on at a fast rate to improve quality and lower files eventually become four plates that run on the costs. printing press at the same time on four cylinders. CMYK is different from the RGB (red, green, blue) Although state-of-the-art commercial printing color model you see on your computer screen. The companies are moving to digital printing, many digital files for every print job are examined and printers still use the tried-and-true offset printing method that has been the standard in commercial adjusted to minimize the number of plates needed to print the project and to convert color images or printing for more than a century. complicated files to only CYMK. Offset lithography — one of the most common way to print ink on paper — uses printing plates to transfer an image to paper or other substrates. The plates are usually made of a thin sheet of metal, but in some instances, plates may be plastic, rubber or paper. Metal plates are more expensive than paper or other plates, but they last longer, produce high-quality images on paper and have greater accuracy than plates made of other materials. Paper plates are usually suitable only for short print runs without close or touching colors that require trapping. Plan your design so that paper plates can be used effectively if you want to save money. Not all commercial printers offer this option. Depending on the size of the finished printed product, several copies of the file may be printed on a large sheet of paper and then trimmed to size afterward. When a job prints on both sides of the sheet of paper, the prepress department may impose the image to print all fronts on one plate and all backs on another, an imposition known as sheetwise, or with both the front and back on An image is put on the printing plates using a photomechanical or photochemical process during a single plate in a work-and-turn or work-and- tumble layout. Of these, sheetwise is usually the a stage of production known as prepress — one most expensive because it takes double the number plate for each color ink to be printed. of plates. Depending on the size of the project, the Printing plates are attached to the plate cylinders number of inks and the size of the sheet of paper, on the printing press. Ink and water are applied the prepress department chooses the most efficient to rollers and then transferred to an intermediary way to impose the project on the plates. cylinder (blanket) and then to the plate, where the ink clings only to the imaged areas of the plate. Then the ink transfers to the paper. 19 Lucid Motif Graphic Industry