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sequoyah
02-05-2009, 04:58 PM
After many years of using Preps in a mixed files mode to output to a SelectSet 7000, I have changed to a pdf to pdf mode sending the Preps imposed pdf to a Trueflow system offsite at another shop.

I have done some 10 jobs so far with almost everything working fine except for this annoying problem:

The contents of the Flat Identifier Text Mark "$JOBID $CUSTOMER $ps_JobTitle Sheet $SIG $COLOR" comes out on the separate color plates with all the colors Knocking out of each other so that most of it is rendered invisible except for the color name since this is different for each plate. But the color name text is broken up by the knockout of the letters from the other colors, with no color name printing without this problem. This is limited to the Flat Identifier Text Mark. All other template marks are printing fine on all the separations.

The pre press operator at the Trueflow shop does not use Preps, and has no idea what may be the cause for this. Does anyone have any insight about this?

Thanks,

Al

tjaeger
02-05-2009, 06:54 PM
Hey Al,

I've got a Trueflow system....version 3.12
feel free to call me on the phone if you want to try a couple scenarios (I've got Preps as well..of course )

-TimJ ( 5 1 7 ) 2 7 9 - 1 3 0 4 e x t 1 1

sequoyah
02-23-2009, 01:17 AM
The attached pdf is output from a Preps pdf job. In the upper half is an InDesign CS3 exported pdf page that has elements with the same characteristics as the ones in the lower half which are from a Preps template.

In the lower half, the Preps shaded rectangle and register marks are output by Preps as Composite.The text mark from the Preps template has the content "Preps Text Mark $COLOR". But note that in the pdf to pdf job Preps has output that text as separated, even though the output pdf is intended for separation by a rip. As far as I can tell this is the normal process.

In the InDesign page most of the text is in Registration color, with the word "OVERPRINT" given the Overprint attribute. The line that starts with"Separated" and followed by the color names is actually four lines of text, each in one of the KYMC colors in that stacking order (the Preps stacking order), and also given the Overprint attribute. This is to imitate the Preps text.

The purpose of this pdf is to test if a TrueFlow rip will handle the InDesign text in the same way it handles the Preps text when doing separations. When examined in Acrobat 8 Pro. the Indesign "Separated" lines and the Preps text all show as overprinting with Color Warnings turned on in Output Preview (see Picture 1 screen capture, and note that the I Design slug info has this as well). But as I explained in my first post in this thread, we are seeing the Preps text Knocking Out all from each other in all colors including the black. The result on each color plate is that "Preps Text Mark Process" disappears, and the color names are chopped up. If those text lines are set to overprint, then why are they knocking each other out? That's the main focus of this thread.

Tim Jaeger was able to reproduce the problem by turning off overprint somewhere in his 3.12 TrueFlow system. But that was with a blank run list page. I am hoping that some of you with newer TrueFlow rips would run this through your system and preview it to see if the InDesign pre separated text is handled in the same way as the Preps text. Tim, please try this file with your system set as you normally set it for your own work.

Thanks for any help and insight,

Al

sequoyah
02-23-2009, 03:47 AM
An additional observation is that if the Preps text mark does not contain the $COLOR variable, then it is output in registration color and without the overprint attribute. This is from testing the pdf in Acrobat Pro. and in Illustrator.

So the stack of overprint and pre separated lines is probably Prep's way of getting the values of the $COLOR variable to the rip when it is not integrated into a larger workflow.

But why do those lines knock each other out when they are set to overprint?

Al

rob.morgan
02-23-2009, 04:44 PM
Al,
The difference between your 2 lines is the top line from InDesign has a stack of objects that use the DeviceCMYK color space while the bottom line contains a stack of objects that paint in Separation color space. I suspect that the RIP has a setting somewhere that converts Separation color space to DeviceCMYK and mistakenly changes the OPM mode to 0.

OPM = 0 makes the channels that paint zero percent tint opaque (i.e knock out) instead of just ignoring them.

You file appears to have its overprints set up correctly on the way in but something must be changing the file or else the RIP is not rendering overprints correctly. The first place I would look is to the settings for color management as color space conversions are the most likely cause of overprint errors. If the RIP creates a temporary PDF after color matching, you might be able to open this and see if the file still looks the same in Acrobat.

Cheers,
Rob

sequoyah
02-23-2009, 05:14 PM
Hi Rob,

Thank you very much for looking at the file. I will ask the TrueFlow shop to investigate your suggestion.

In the meantime, can you please explain how you determine the color spaces of those two lines. Can I do that with Acrobat 8 Pro., or do I need a heftier pdf tool for that?

Thanks,

Al

rob.morgan
02-23-2009, 05:31 PM
In acrobat 9, the Output Preview tool has an "Object inspector" that will tell you information like object type, color space, overprint state, etc of all the objects in a stack under your cursor. You could also use PitStop which lets you select individual objects and make changes if the objects are defined incorrectly.

Rob

sequoyah
02-24-2009, 04:10 PM
The verdict is in,

The envelope please...(drum roll).

It's a TrueFlow issue! The test file was ripped, and the magenta separation plated: the Indesign line was treated the same as the Preps line. The text "Separated" disappeared, and the color names appeared broken up by their mutual knockout effect. So in this particular installation, the TrueFlow rip is not honoring overprint.

Next move: call Screen tech support.

Thanks to Tim and Rob for the input.

Al

sequoyah
02-28-2009, 04:16 AM
Final post to close the thread.

The TrueFlow shop received instruction from tech support on turning on using application overprint. Now both the InDesign stacked lines and the ones from the Preps template text mark print complete on each separated plate without the knock out problem.

So this a TrueFlow problem due to an incorrect setting, and did not involve a color conversion.

Al