Scaling - Xerox DocuColor DocuColor 4 User Manual

Image quality
Print the files and examine the output. You will likely begin to see a marked
deterioration in output quality at resolutions below 200 ppi, while above
200 ppi the improvement may be very subtle.
Raster images prepared for offset printing may need to be at higher resolu-
tions than needed for proofing on your DocuColor 4 LP.
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6.5.2

Scaling

Ideally, each raster image should be saved at the actual size it will be placed
into the document and at the optimal resolution for the print device. If the
image resolution is correct for the print device, there is no quality advantage
to be gained by scaling an image down to a percentage of its actual size. If
you scale a large image down to a percentage of its actual size, you incur
unnecessary file transfer time because the image data for the entire large
image is sent to the printer. If an image is placed multiple times at a mark-
edly different sizes in a document, save a separate version of the image at
the correct size for each placement.
If you need to place an image at greater than 100% in a document, remember
that the output image resolution is affected. For example, if you scale a 200
ppi image to 200%, the image is printed at 100 ppi.
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6.5 Optimizing files for processing and printing
100 ppi 200 ppi 300 ppi
Image resolution
400 ppi