HELP! BIZZARE Fiery tinted backgrounds from PDF PROBLEM!

  • Thread starter Thread starter TekWiz
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TekWiz

Hi! I am trying to help someone who has a major problem with
backgrounds showing a tint when printing from Acrobat. It's like a
greenish tint. The problem wasn't always there. Usually it's a
graphic--like a scan, where the white area would show up as a tint.

I tried fixing one PDF, and I exported to Photoshop as tiff, and found
that the white areas were 255,255,250, so I upped the red a bit by
like 5% and then the whites didn't have the tint anymore (in fact the
tint was affecting the whole document).

THE WIERD THING IS: The SAME PDF was printed on various other printers
and there was not tint. Looks like the difference between Red 250 and
255 isn't enough to show as a tint, but for some reason something is
exaggerating it.

The printers are a Xerox 3535, and a Xerox 7300. The driver is the
Fiery PS driver.

I've seen some similar questions years ago, and the answer was that
the video card or monitor were misadusted but that makes no sense
because as I'm saying the same files will print elsewhere fine, and
the problem was not there before. I suspect it's a driver/or
misconfiguration problem... Just don't know how to get rid of it.

Thanks for any insight...

Tek.
 
TekWiz said:
I've seen some similar questions years ago, and the answer was that
the video card or monitor were misadusted but that makes no sense
because as I'm saying the same files will print elsewhere fine, and
the problem was not there before. I suspect it's a driver/or
misconfiguration problem... Just don't know how to get rid of it.
Click to expand...

Have you got any colour management things (ICM or some colour profile)
running in the printer driver, if so try turning all colour management
off and see if that makes a difference.
 
I analyzed the whole situation and you are right--it's a color
management issue. Documents with no color management in them, get
managed by incorrect settings in the RIP so white graphics tend to
come out tinted green.
 
Oh, lemme add that in fact, Xerox addresses this exact issue on their
website!


Correcting for white Photoshop background that prints as a very light
color

Do one of the following to alleviate the problem of the white
background printing as a very light color.


Verify the image contains pure white by referencing the CMYK and RGB
percentages in the Info palette

Convert the file format for the image from RGB to CMYK, then try
printing again.

After selecting Print, click Print in CMYK in the Print dialog box.
If using the RGB format is necessary, the problem can be corrected by
changing the white point of the monitor, which is adjustable from
Photoshop. If background whites are printing with a yellowish tint,
then the white point value is too low and should be increased. If
background whites are printing with a bluish tint, then the white
point value is too high and should be decreased. The default value is
6500 K.

To change the white-point value for the monitor, do the following:


In Photoshop versions 3 and earlier: From the File menu, select
Preferences.
In Photoshop version 4: from the File menu, select Color Settings.
In Photoshop versions 5.5 and 6: from the File menu, select Color
Settings.

Select Monitor Setup or RGB Setup.

Select White Point, then alter the value as needed.

Other factors may also contribute to this effect:
Because of differences in monitors and printers, it is common for an
image to contain residual data in the white areas that will not show
on the monitor, but will on printed output. It is important to make
sure that it is a pure white background that is being printed, not
some very light color, such as two-percent yellow. Use the Info
palette to see the CMYK and RGB values of the pixels under the
pointer. When the RGB values have all reached 255 and/or the CMYK
values are all at 0%, you have attained a pure white.

Check the TekColor correction in use (available from the Print dialog
box). Using the SNAP Press correction can cause a slight coloring of
the background in some cases. Select a different TekColor correction.
Commercial Press. is recommended for CMYK images and Vivid Blue for
RGB images.

If the image is imported into QuarkXPress from Photoshop, be sure that
the background is set to None for that image. Also, from the Page
Setup menu in QuarkXPress, set EfiColor Profile to None.

If printing from a Macintosh running System 7.5, select Control Panels
from the Apple menu, then select Extensions Manager. Make sure that
QuickDraw GX, QuickDraw Help, and ColorSync are all disabled, unless
QuickDraw and/or ColorSync are specifically in use.

Historically, printing presses have used the four-process (CMYK) color
separations for printing a wide range of color, requiring images to be
separated into four separate plates. With digital imaging, files are
scanned in an RGB format, requiring a translation before going to
press; hence, the use of CIE Lab to map colors between RGB and CMYK It
is this translation and mapping that results in shifts between RGB and
CMYK, as stated above.
 
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