Selecting Halftone Screen Attributes - Adobe PHOTOSHOP 5.0 User Manual

Border Lets you print a black border around an
image, specifying its width in the unit of
measurement you choose.
Lets you print any caption text entered in
Caption
the File Info dialog box. (See "Adding file infor-
mation" on page 313.) Caption text always prints
as 9-point Helvetica plain type.
Lets you select a background color to
Background
be printed on the page outside the image area. For
example, a black or colored background may be
desirable for slides printed to a film recorder. To
use this option, click Background, and then select
a color from the Color Picker dialog box. This is a
printing option only and does not affect the image
itself.
Lets you print crop marks inside rather than
Bleed
outside the image. Use this when you want to trim
the image within the graphic. You can specify the
width of the bleed.
Lets you adjust the transfer functions,
Transfer
traditionally used to compensate for dot gain or
dot loss that may occur when an image is trans-
ferred to film. This option is recognized only when
you print directly from Photoshop, or when you
save the file as EPS and print to a PostScript
printer. Generally, it's best to adjust for dot gain
using the settings in the CMYK Setup dialog box,
but transfer functions also are useful for compen-
sating for a poorly calibrated output device. (See
"Compensating for dot gain in film using transfer
functions" on page 95.)
Selecting halftone screen
attributes
Halftone screen attributes include the screen
frequency and dot shape for each screen used in
the printing process. For color separations, you
must also specify an angle for each of the color
screens. Setting the screens at different angles
ensures that the dots placed by the four screens
blend to look like continuous color and do not
produce moiré patterns.
Before creating your halftone screens, check with
your print shop for preferred frequency, angle, and
dot settings. (Use the default angle settings unless
your print shop specifies changes.)
Note: Halftone screen attributes are recognized only
when you print directly from Photoshop, or when
you save the file as EPS and print to a PostScript
printer.
About halftones
Halftone screens consist of dots that control how
much ink is deposited at a specific location on-
press. Varying their size and density creates the
illusion of variations of gray or continuous color.
For a process color image, four halftone screens are
used: cyan, magenta, yellow, and black—one for
each ink used in the printing process.
For a color illustration of halftone screens,
see figure 15-1 on page 228.
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User Guide