computer2plate-direct2plate



**Computer to ****Plate (CTP ****) **  also known as **Direct to Pla****te** (DTP) is an imaging technology used in modern printing processes. In this technology,an image created in a **Desktop Publishing** (DTP) application is output directly to a printing plate.This compares with the older, **Computer to Film** (CTF), where the computer file is output onto a photographic film. This film is then used to make a printing plate, in a similar manner to a contact proof in darkroom photography.

 **Computer to plate** printing is a new technology that eliminates the use of film in printing.Traditional methods of printing, called offset lithography printing,produced film on an imagesetter and used it tomake a metal printing plate.The plate went

 plate. The plate then went on a printing press to make the printed impressions. With direct to plate printing, the printing plate is produced directly from a computer, eliminating the need for film.Computer to plate is becoming very popular dueto its cost-effectiveness. Production of film costs a great deal of time andmoney, and computer to plate has cut out the middleman in order to save on both.CTP is also environmentally friendly and has a higher productivity rate. Without the use of film in the Printmaking process, the technology has had to evolve and expand to maintain the quality of the prints.Some print manufacturers have brought out their own development techniques to make sure there is no loss of quality with the elimination of film.Kodak has developed the Direct Thermal Printing Plate, which uses thermal imaging techniques as opposed to the silver halide or photopolymer technologies used by others.

__ Laser Types __ To date, there have been three styles of lasers used to make steel and polymer plates: diode-pumped YAG, Ytterbium fiber laser (YAG wavelength), and CO2. The primary differences between these units are the maintenance required, the spot size, and ability to ablate (etch) various materials.  Maintenance**-** The diode-pumped YAG has a diode bar that heats up and can warp after about 10,000 hours of use, thereby requiring costly replacement. The fiber laser has no diode bar and therefore, has no maintenance for up to 70,000 hours of operation. The CO2 laser also does not require a significant amount of maintenance. Spot Size. The wavelength of a YAG laser (1.064 microns) is exactly ten times smaller thanthe CO2 wavelength (10.64 microns) and therefore, has a resulting spot size that is 10 times smaller than a CO2 (in the same set-up). YAG lasers are able to provide more detailed graphics than CO2 when both laser types are put into the same machine set-up. Materials. YAG lasers are ideally suited for metals, but their wavelengths are not easily absorbed by many other materials (wood, acrylic, plastics, fabrics, etc.) A CO2 laser beam has much more latitude and can be absorbed easily by many organic materials such as wood, paper, plastics, glass, textiles, and rubber, but is not easily absorbed by metal.  __<span style="background-color: #caf7eb; color: #008080; font-family: 'Bernard MT Condensed'; font-size: 150%;">Colour Separations __ <span style="background-color: #caf7eb; display: block; font-family: 'Comic Sans MS',cursive; text-align: justify;"> ** Colour separations ** created from photographic methods are <span style="background-color: #caf7eb; display: block; font-family: 'Comic Sans MS',cursive; text-align: justify;"> used to prepare plates for traditional printing methods. Each <span style="background-color: #caf7eb; font-family: 'Comic Sans MS',cursive;"> of the plates match to one of the four colours, cyan, magenta    <span style="background-color: #caf7eb; display: block; font-family: 'Comic Sans MS',cursive; text-align: justify;">, yellow , or **black**. The plates are coated with the <span style="background-color: #caf7eb; display: block; font-family: 'Comic Sans MS',cursive; text-align: justify;">corresponding ink colours when being printed. The inked <span style="background-color: #caf7eb; display: block; font-family: 'Comic Sans MS',cursive; text-align: justify;">image from the plates is then transferred to the substrate. <span style="background-color: #caf7eb; display: block; font-family: 'Comic Sans MS',cursive; text-align: justify;"> The varying sizes of the halftone dots on the plates, determines the amount of ink that will be printed on the substrate. The dots from each of the different coloured images overlap to produce the full colour image.

<span style="background-color: #caf7eb; font-family: 'Comic Sans MS',cursive;"> <span style="background-color: #caf7eb; font-family: 'Comic Sans MS',cursive;"> __CTP__ __Te__ __chnology__ <span style="background-color: #caf7eb; font-family: 'Comic Sans MS',cursive;">The first CTP solutions were unveiled at the end of the 1980's. <span style="background-color: #caf7eb; font-family: 'Comic Sans MS',cursive;">Investment in the early 90's for the CTP system provided  <span style="background-color: #caf7eb; font-family: 'Comic Sans MS',cursive;">printshops with scope for better market positioning. It enabled <span style="background-color: #caf7eb; font-family: 'Comic Sans MS',cursive;">them to differentiate themselves from other companies. Ctp <span style="background-color: #caf7eb; font-family: 'Comic Sans MS',cursive;">has become very established as a standard process in all the  <span style="background-color: #caf7eb; font-family: 'Comic Sans MS',cursive;">industrial countries. The first CTP recorders were categorized <span style="background-color: #caf7eb; font-family: 'Comic Sans MS',cursive;">depending on their design, into internal drum, external drum  <span style="background-color: #caf7eb; font-family: 'Comic Sans MS',cursive;">or flatbed devices. <span style="background-color: #caf7eb; color: #1ea4e6; display: block; font-family: 'Comic Sans MS',cursive; font-size: 180%; text-align: left;">HOW IS CTP USED? <span style="background-color: #caf7eb; color: #008080; display: block; font-family: 'Comic Sans MS',cursive; text-align: left;">__ **Computer to plate engine for the** ____ **<span style="display: inline !important; text-align: left;">newspaper industry ** __ <span style="background-color: #caf7eb; font-family: 'Comic Sans MS',cursive;">media type="youtube" key="ryYLM46K_XI" height="350" align="left" width="425"





= = =<span class="mw-headline" style="background-color: #caf7eb; font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Types of CTP-Plates (Com **<span class="mw-headline" style="background-color: #caf7eb; font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">puter-to-plate) ** = === <span class="mw-headline" style="background-color: #caf7eb; color: #0000ff; font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Photopolymer plates  ===
 * photosensitivity between 400 to 550 nm
 * low laser energy of 100 to 200 µJ/cm2 needed for exposure
 * run lengths of up to 200.000 prints

<span style="background-color: #caf7eb; color: #808080; font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif; font-size: 17px;"> Silverhalogen plates

 * silverhalogen aluminium printing plates
 * photosensitivity between 400 to 700 nm
 * low laser energy of 1 to 2 µJ/cm2 needed for exposure
 * run lengths of up to 150.000 prints
 * resolution to 250 LPI possible
 * dot reproduction 1–99 %

<span class="mw-headline" style="background-color: #caf7eb; color: #ff0000; font-family: Georgia,serif;">Thermal plates
<span style="background-color: #caf7eb; font-family: 'Comic Sans MS',cursive;">__**References**__
 * photosensitivity between 830 to 1.070 nm
 * high laser energy of up to 500 µJ/cm2 needed for exposure
 * run lengths of up to 100.000 prints
 * resolution to 200 LPI possible
 * dot reproduction 1–99%
 * high process stability
 * many providers
 * processing in the daylight possible
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