Adobe Photoshop CS4 - Manual (Page 486)

479 Last updated 1/10/2010
Chapter 16: Printing
Printing is the process of sending your image to an output device. You can print on paper or film (positive or negative),
to a printing plate, or directly to a digital printing press. Before printing, you can preview your image in full color using
color management options from the Print dialog box.
Printing from Photoshop
About printing
Whether you are printing an image to your desktop printer or sending it to a prepress facility, knowing a few basics
about printing makes the print job go more smoothly and helps ensure that the finished image appears as intended.
Adobe® Photoshop® CS4 supports printing documents greater than 30,000 pixels, and (Mac OS only) can send 16-bit
per channel data to printers.
Types of printing For many Photoshop users, printing a file means sending the image to an inkjet printer. Photoshop
can send your image to a variety of devices to be printed directly onto paper or converted to a positive or negative
image on film. In the latter case, you can use the film to create a master plate for printing by a mechanical press.
Types of images The simplest images, such as line art, use only one color in one level of gray. A more complex image,
such as a photograph, has varying color tones. This type of image is known as a continuous-tone image.
Halftoning To create the illusion of continuous tones in images, printers break down images into dots. For photos
printed on a printing press, this process is called halftoning. Varying the sizes of the dots in a halftone screen creates
the optical illusion of variations of gray or continuous color in the image.
Note: Although inkjet printers also use dots to create the illusion of continuous tones, their dots are of uniform size and
much smaller than the dots used by most printing presses.
Color separation Artwork intended for commercial reproduction and containing more than one color must be
printed on separate master plates, one for each color. This process, called color separation, generally calls for the use
of cyan, yellow, magenta, and black (CMYK) inks. In Photoshop, you can adjust how the various plates are generated.
Quality of detail The detail in a printed image depends on its resolution and screen frequency. The higher the
resolution of an output device, the finer (higher) a screen ruling (lines per inch) you can use. Many inkjet printer
drivers offer simplified print settings for higher quality printing.
About desktop printing
Unless you work in a commercial printing company or service bureau, you probably print images to a desktop printer,
such as an inkjet, dye sublimation, or laser printer, not to an imagesetter. Photoshop lets you control how your image
is printed.