| Good quality
halftone reproduction in the newspapers requires an
85-line screen for black and white, and for spot
color printing. A 85-line screen works best for
process color work. Screens should be round dot and
conform to standard screen angles. An output of
approximately 1000 dots per inch, and not less then
600 dpi, is recommended.
Halftone scans should accommodate a 30 to 35%
midtone press gain, allowing for the spread of ink
(dots) in the press reproduction process. Unless
proper adjustments are made in the prepress stage,
images will reproduce darker and flatter than the
original.
This can best be accomplished by using the
"curves" menu and "unsharp mask"
filters in Photoshop, or other image editing
software. In the curves menu, a good rule of thumb
would be to set the highlight dot at 2 or 3, the
shadow dot between 85 and 90, and pull the weight in
the midtones from a 50% dot to approximately 35%.
This will give the image a "washed out"
appearance. It's okay if highlight dots are dropped
from non-detail whites.
To sharpen your image in Photoshop using the
unsharp mask filter, good results can be achieved by
setting the radius for 1.5, the threshold for 7, and
sharpening in amounts of 50 (50, 100, 150, etc).
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