Photoshop CS3 for Screen Printers- P18

Photoshop CS3 for Screen Printers- P18: The toolbox is the heart of Photoshop CS3, and where you’ll find thetools you need to create your artwork and perform editing tasks. Fromthe toolbox you can access the selection tools, shape tools, type tools,Crop tool, and eraser tools. These are basic tools that any screen printeror graphic artist needs.
Nội dung trích xuất từ tài liệu:
Photoshop CS3 for Screen Printers- P18486 Part V / Color Separations DCS 2.0 is supported by several other programs, including Adobe Page- Maker, Adobe Illustrator, and QuarkXPress. If you are preparing an image with spot colors for printing from another application, consider uncheck- ing Include Halftone Screen and select Include Transfer Function.Resolutions A big part of successful color separations and screen printing is working with the right resolution. Different types of resolution have been intro- duced briefly in this book in various chapters and for various hardware and software, but you need a firm grasp on the concept to truly under- stand the importance of it. Image Resolution When an image is printed, an image with a high resolution contains more pixels than a low-resolution image, and the pixels are smaller. Consider this: A 2 inch by 2 inch image with a resolution of 72 dots per inch cre- ates (144 pixels by 144 pixels) 20,736 pixels. The same 2 inch by 2 inch image created and printed at 200 dots per inch creates (400 pixels by 400 pixels) 160,000 pixels. At 600 dots per inch, this escalates to 1,440,000 pixels. Because there are more pixels created for the same size image, the image will print out with more detail than a low-resolution image. This is why low-resolution images get a “pixelated” look. You can actually see the pixels on the page, making low-resolution prints difficult to work with at the press. In contrast, using a resolution too high for the output device or substrate that it is printed on is a waste of resources and time. The object, of course, is to find a happy medium.. Note: Image resolution is measured in pixels per inch (ppi). Chapter 26 / More about Color Separations 487 Printer Resolution Printers can print in many different resolutions and the resolution quality is generally proportional to the price of the printer. Wide format thermal imagesetters usually print at resolutions between 400 dpi and 1200 dpi to 2450 dpi and higher, depending on how much you invest. The technology is always growing though, so you can always expect more in the future. These wide format printers can print directly on the film too, reducing the steps (and thus dot gain) associated with other types of printers. Laser printers can print various resolutions, but they generally print between 300 dpi and 600 dpi; however, some expensive laser printers print as high as 1200 dpi or more. Inkjet printers usually don’t print this high, and the low-end printers average around 300 dpi. You get what you pay for.. Note: Printer resolution is measured in dots per inch (dpi). Screen Resolution and Frequency Line screen, also called screen ruling, is how many lines of halftone dots appear per linear inch on a printed page, positive, or negative. Line screen is measured in lines per inch (lpi). It is limited by the output device and the paper, film, or fabric you print on. Common settings for screen printers range from 55 lpi to 65 lpi. Newspapers print around 85 lpi and magazines around 133 or 155 lpi. When thinking about lpi settings, consider this: A 300 to 600 dpi laser printer can usually only print at an lpi of 55 to 65, and better print- ers get a better lpi. Some screen printers have the ability to print at 85 to 100 lpi, and they get good results with good equipment. Obviously, a higher line frequency will produce sharper images; however, the limita- tions of the film, paper, printer, and screen, along with various associated costs, make obtaining a high lpi for screen printing unreachable for most of us.488 Part V / Color Separations When you print out color separations using Photoshop’s Print com- mand, you can set the frequency of the halftone screens. Figure 26-5 shows the Halftone Screen dialog box. Figure 26-5: Setting screen frequency Though theories vary, in Chapter 29 we discuss the most common set- tings for the various plates and how to configure them. For most screen printers, an lpi of 55 to 65 is reasonable.. Note: Screen (press) resolution is measured in lines per inch (lpi). Mesh Count Mesh count is denoted by a number that increases as the fineness of the mesh does. Mesh counts for screen printers generally range between 110 and 205 for plastisol inks, simple spot color prints, and direct prints, and 110 to 380 for other types of prints, including process prints. You determine the mesh count ...