Adobe illustrator 10 Manuale Utente
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Adobe Illustrator Help
Producing Color Separations
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The PPD files for high-resolution imagesetters offer a wide range of possible line-screen
rulings paired with various imagesetter resolutions. The PPD files for lower-resolution
printers typically have only a few choices for line screens, and they are coarser screens of
between 53 lpi and 85 lpi. The coarser screens, however, give optimum results on lower-
resolution printers. Using a finer screen of 100 lpi, for example, actually decreases the
quality of your image when a low-resolution printer is used for final output.
rulings paired with various imagesetter resolutions. The PPD files for lower-resolution
printers typically have only a few choices for line screens, and they are coarser screens of
between 53 lpi and 85 lpi. The coarser screens, however, give optimum results on lower-
resolution printers. Using a finer screen of 100 lpi, for example, actually decreases the
quality of your image when a low-resolution printer is used for final output.
To specify a halftone screen ruling and resolution:
1 In the Separation Setup dialog box, choose one of the following options:
•
To select one of the preset halftone screen ruling and printer resolution combinations,
choose an option from the Halftone pop-up menu.
•
To specify a custom halftone screen ruling, select the plate to be customized and then
enter the lpi value in the Frequency text box and a screen angle value in the Angle
text box.
text box.
Note: The default angles and frequencies are determined by the selected PPD file. Be sure
to check with your print shop for the preferred frequency and angle before creating your
own halftone screens.
to check with your print shop for the preferred frequency and angle before creating your
own halftone screens.
2 Specify another separation option, or click OK.
Specifying the page size and orientation
Adobe Illustrator normally uses the page size default in the PPD file for the selected
printer. However, you can change the page size to any of the sizes listed in the PPD file as
well as specify portrait (vertical) or landscape (horizontal) orientation. Page sizes are listed
by familiar names (such as Letter) and by dimensions in points. The dimensions shown in
parentheses after the page size are the limits of the imageable area. The imageable area is
the total page size less any unprintable border used by the printer or imagesetter. Most
laser printers cannot print to the exact edge of a page.
printer. However, you can change the page size to any of the sizes listed in the PPD file as
well as specify portrait (vertical) or landscape (horizontal) orientation. Page sizes are listed
by familiar names (such as Letter) and by dimensions in points. The dimensions shown in
parentheses after the page size are the limits of the imageable area. The imageable area is
the total page size less any unprintable border used by the printer or imagesetter. Most
laser printers cannot print to the exact edge of a page.
If you select a different page size (for example, change from letter to legal), the artwork is
rescaled in the preview window. This is because the preview window displays the entire
imageable area of the selected page; when the page size is changed, the preview window
automatically rescales to include the imageable area.
rescaled in the preview window. This is because the preview window displays the entire
imageable area of the selected page; when the page size is changed, the preview window
automatically rescales to include the imageable area.
Note: The imageable area may vary by PPD file, even for the same page size (for example,
Letter), because different printers and imagesetters define the sizes of their imageable
areas differently.
Letter), because different printers and imagesetters define the sizes of their imageable
areas differently.
Make sure that your page size is large enough to contain your artwork as well as crop
marks, registration marks, and other necessary printing information. To conserve image-
setter film or paper, however, select the smallest page size that accommodates your
artwork and necessary printing information.
marks, registration marks, and other necessary printing information. To conserve image-
setter film or paper, however, select the smallest page size that accommodates your
artwork and necessary printing information.
To specify a page size:
1 In the Separation Setup dialog box, choose an option from the Page Size pop-up menu.
2 Specify another separation option, or click OK.
To specify the orientation of the page:
1 In the Separation Setup dialog box, choose Portrait or Landscape from the Orientation
pop-up menu.
pop-up menu.