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CS2 Drop shadows are CMYK not black, help.

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garda09

Technical User
May 4, 2007
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GB
I'm working on a Greyscale job so we just want to output to one plate but whenever we include a drop shadow, it outputs to 4 plates, even if the colour of the drop shadow is set to black.

Is there any way of getting a black (single plate) output when I include drop shadows?

Cheers,

DG
 
Are you placing RGB art? What colorspace is being used for transparency flattening?
 
Have you checked the CMY plates in the separation preview to see if there's anything there? I just did a quick test document and they showed blank, while the black plate showed the actual black text with the shadow. If that's okay, you could just output the black plate when printing separations.



Using OSX 10.3.9 on a G4
 
HI GUYS. Thanks for the suggestions.

OK, Firstly, it doesn't matter what artwork you place in the picture boxes with the drop shadows. If you just have the drop shadows on a picture box without any content, we still get CMY plates. However, to answer you question, we're placing Greyscale TIFFs.

Secondly, we've checked the CMY plates in Acrobat and there's nothing there. However, for some reason, the printer (who prints all of these books digitally) can't run these pages as black only and is rejecting them.

If I take these Greyscale pages and produce a PS file as a Greyscale composite, then distil that file, I get a perfect Greyscale output on one plate. Great you might think. Except that some of the pages in these books are colour and some Greyscale. So, I'm trying to reduce the steps involved here and ideally I want to run the whole job as one PDF (because we have about 400 of these books to do this year). It really does seem to be the drop shadows that cause the problem.

I read on another thread something about blend spaces and dropshadows causing a CMYK output but don't know if its relevant.

Any ideas?
 
Here's something to do as a test. Create a new 1 page ID doc and stick one of those grayscale tiffs in there, WITHOUT the shadow. If you then go to separation preview in ID, I think you'll again see the CMY plates. At least in the version I use (CS1) there is no way to work in pure grayscale or b&w. I've tried trashing the CMY swatches and still get the CMY plates in docs that only use pure black.

I have to do the grayscale postscript - Distiller thing all the time for newspaper ads that require grayscale only. If I don't do that, the pdf always has CMY in it even with no color at all in the original ID doc. Same thing goes when I view separation preview in the original ID - the plates are always there - and blank. I hardly ever use drop shadow, so that's not it.

Since your books are both gray and color and you want to run them from one pdf, I'd assume that it would be easiest to just run the thing with the blank CMY plates. It will look the same, just not use any CMY ink.

If you want to I assume you could do the grayscale PS - Distiller thing with the gray pages and a standard color pdf for the rest and then combine them in Acrobat pro. I've never done that so I don't know how your printer would handle it.


Using OSX 10.3.9 on a G4
 
Tried that just now.

With drop shadow, Acrobat sees multiple plates.

Without dropshadow, single black plate.

Thanks for your asssitance, I do appreciate the help.

 
...you appear to contradict in these to statements:

>>> Secondly, we've checked the CMY plates in Acrobat and there's nothing there. However, for some reason, the printer (who prints all of these books digitally) can't run these pages as black only and is rejecting them. <<<

...that statement above points to your printers rip applying a conversion...

>>> With drop shadow, Acrobat sees multiple plates. <<<

...with this statement your issue points to a converion on your own desktop...

...confused as to how on one output acrobat previews seps fine and in the other acrobat no longer previews seps correctly...

...can you clarify?

Andrew
 
...i would verify that the drop shadow black you are selecting really is just black...

...if your blend space setting is rgb you will end up converting your blacks to cmyk, but this would effect all text too...

...distiller is also capable of converting black to cmyk depending on your distiller settings...

...export directly to pdf rather than postscript to distill, if this gives the same result, it is the blend space in rgb, distiller doing an unwanted conversion or your print provider doing an unwanted conversion somewhere in the workflow...

Andrew
 
Hi andrew.

To clarify, when we preview the separations in Arcobat, there is no ink coverage on the CMY plates but they have still been produced within the PDF. All the ink is on the black separation.

When we composite greyscale ps and distill, the PDF is produced in only black, no CMY separations.

The blend space is CMYK in the original Indesign file by-the-way.

I'm confused too.
 
...ok, so your ideal scenario is that you wish to have pdf files with only black seps i.e. one plate per page of pdf...

...the issue with cmyk composite pdf output is that you have registration marks which will be produced on the cmy plates even if no artwork exists on these plates...

...i imagine your printer is rejecting these as they would prefer (to save checking all ripped seps) to have black only. This would save them time from verifying that the CMY seps that are being produced really are NOT containing rogue artwork. Doing this is then reliant on the client providing correct artwork on one plate as you mention...

...composite greyscale is a different output scenario as reg marks will then only be in a greyscale colour space...

...this is the nature of composite output a lot of the time...

...doing the composite greyscale is OK, as would printing to separations from indesign and distilling, the seps route would however mean your artwork needs to be spot on so that black really is black and not a mix of cmyk etc...

Andrew
 
Thanks for looking at this one Andrew. If you're talking about the printers reg marks, it can't be that because none are being output to the PDF. No printers marks are being used at all.

This has got to be something to do with flattening the drop shadow and blend modes which convert the page to CMYK. I'm outputting a PDF 1.3 so the flattening occurs pre RIP.

The ideal situation is to run one PDF with CMYK pages and black only pages in the same document, where the CMYK pages produce CMYK separations and the black only pages produce black.

Any other ideas 'cause this is wierd.
 
..when you say outputting, are you exporting from indesign to pdf or printing to postscript then distill to pdf, these are two quite different ways...

...if it is the distiller, postscript route, i strongly suspect your distiller settings are causing shifted output...

...does exporting produce the same result as distilling?

Andrew
 
Output - directly from ID to PDF.

When I follow ps-distill route, no problems.
 
Go to Edit > Transparency Blending > Document
and click CMYK. (I think you have RGB selected), If that is not the case, please send me the problem page at virendrab@shaw.ca

Good luck!

jdguru
 
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