Converting colors

rande

Well-known member
I have a file that looks two color but isn't.
There's a pantone 350 and black then some gradients and halftones that are 4c. Isn't there away to change that
in Acrobat 9 to make the gradient grayscale and leave the pantones alone?
In fixups there's convert to cmyk keep spot color.
There's convert to grayscale including spot.
I'm looking for convert to grayscale excluding spot colors.
Is there away to change that? I'm not seeing it.
 
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You can make your own fixup, or use the colour converter.
The colour converter is the yellow to blue gradient in the prepress tools.
You can choose per colour space and convert to grey. It would mean once for CMYK and once for RGB? You can even run the commands by type (eg text object, images etc)

You can even save your "recipie" as a preset.

There is also PitStop, Calas as alternatives, but you probably know that.

If you have complex colour reductions it would be good to look into Illustrators recolour artwork tool.
Also great pluggins from Phantasm CS and Esko for Illustrator.
 
Depending on how complex and how many changes there are you may want to look to PitStop Extreme.
 
Here's the file.
I want ot keep the pantone and change the rest to
grayscale.
 

Attachments

  • test page.pdf
    890.8 KB · Views: 193
The file when I look at it in PitStop Extreme is k and PMS. The problem is you have some profiles in there that are being processed and giving you the 4/c blacks. Get rid of the profiles, get rid of the problem. You don't want the objects as gray since you need some of them to overprint.

Looking at the video you can see that when I map the entire process black channel to Pantone 032 Red C that everything that was K is now 032 Red.

Matt Beals, 2010

Attached is the processed PDF.
 

Attachments

  • test page_mapped.pdf
    551.4 KB · Views: 201
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How? I've been looking around. In 9.0 I've looked thru fixes. I see convert to cmyk excluding spot but not grayscale.
I have Pitstop 7.1 in Acro 7.1.0. and I'm not finding anything yet; still looking. I was sure there's
something in there. In actions or preflight? Just not seeing it.
My partner has pitstop in acro 6 and he has one of the daults. "All gray to real gray" but that
doesn't work on my machine.
 
I've looked thru the preflight that worked. I want to get that into Acrobat 9.0.
I'm not seeing where to change that. I've never done a fix or a profile, I've never needed to.
I'm not seeing where I replace with real gray and real black.
Can anyone point me in the right direction?
thanks
 
Also, where can I find an easy explanation of why and at what times I would convert
PDFs to PDF/x-1 or -3 or a-1a etc.?

I've been working with PDFs for 9 years and have never converted one to any of these.
I might have gotten some from clients which I think is why can't manipulate the files.
I chunks them all out so I can't make any changes. I think its been a problem on some traps
also.
 
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The file when I look at it in PitStop Extreme is k and PMS. The problem is you have some profiles in there that are being processed and giving you the 4/c blacks. Get rid of the profiles, get rid of the problem. You don't want the objects as gray since you need some of them to overprint.

Looking at the video you can see that when I map the entire process black channel to Pantone 032 Red C that everything that was K is now 032 Red.

Matt Beals, 2010

Attached is the processed PDF.

Just saw your video. Pretty slick. I don't have Extreme. Is that a lot better? Very expensive.
I don't understand the profiles enough to trash the right one. I've just used the ones that come with it.
 
@rande the x standards are a subset of PDF, usually i don't convert to them, but ask customers to conform to them. PDFx1a is usefull in that it will be very consistenty image independant of RIP for the same printing technology, eg any sheet offset press with correct TVI curves and on the same substrate. The PDFx4 is better as it does not flatten work, but still has an output intent so you know what press it was prepared for, older rips however can image this inconsistently, and they require a correct configuration of rip and colour management. Consider it like saying when you recive a quote you want them to tell you wich currency it was in, and not find out when they drain your bank acount.
 
Rande, PitStop Extreme is not cheap. But there isn't much that you can't do with it.

I encourage everyone to use the PDF/X standards when working with external and internal resources. All PDF/X really says is that you have met a certain number of minimum requirements. Such as fonts are embedded, you have defined a size of the job, you have prepared it for a certain printing condition, you haven't used certain image compression types. PDF/X-1a builds on those basic requirements and additionally says "no color management/ICC profiles" (it's been pre-converted), no RGB or LAB colors, transparency must be flattened, and a few other little details. PDF/X-4 however says that you can have ICC profiles, you can have RGB and you can have live transparency.

PDF/X-1a is great for "blind exchange" where someone who doesn't know anything about your environment, or you, can prepare a page and ensure that it will contain everything necessary to image. Since you don't know how someone will flatten the art you (as part of the PDF/X-1a standard) flatten the art for them. It's the lowest common denominator. You can pretty well assume that anyone who can print a PDF can print a PDF/X-1a.

PDF/X-4 is even better because it allows for things like optional content groups (analogous to layers), ICC profiles (so you can properly convert colors) and live transparency (so you can flatten it they way you need to). But PDF/X-4 also requires a bit of communication so that someone doesn't go and do something stupid. But again, being a standard someone receiving a PDF/X-4 file will have everything contained in the PDF (since it is a content container) to reproduce the job. But it will take a little extra effort on the printers part to ensure that their RIP can properly render a PDF/X-4. Once the printer is confident in their processes and processing then I'd switch over to PDF/X-4.

The PDF/X standards don't really say anything like "this is CMYK only" or "images must be 300 DPI". Companies or organizations add those requirements to PDF/X to suit their particular needs. There is no reason that you cannot have a PDF/X-1a:2003 for a black and white job to be printed on a Xerox Nuvera. Similarly there is no reason that you cannot have a PDF/X-1a:2003 file that contains 8 spot colors. Or a PDF/X-4:2008 that has no live transparency but does have optional content groups.

Groups like the Ghent Work Group have developed "PDF/X-Plus standards". Way back when there was the idea of "PDF/X-Plus" to suit specific vendors/manufactures requirements. But everyone had their own "X-Plus" flavors. The GWG brought a bit of sanity to the world of PDF/X-Plus by further refining the ISO standards into logical groups of specifications. For example, magazines generally don't run spot colors but CMYK only, they like to have images at 300 DPI. So they came up with a agreed "standard" for lack of a better term. Then they did the same thing for newspapers, web offset, etc. Each segment had their own particular needs so they developed a specification for each based on those needs. It wasn't just the GWG that came up with these additional requirements. The GWG developed them with vendors in those particular segments.

Really when you look at each vendors PDF requirements you will find that everyone is basically looking for the same things but with slight variations. The GWG consolidated all those various "personal standards" into something more flexible.

But... Having said all of that PDF/X does nothing to say that you cannot edit or manipulate a PDF. So I suspect that your PDF editing tools aren't up to snuff (or date possibly). PitStop Pro 9, Callas pdfToolbox 4.x and Acrobat 9 should allow you to make most all of the changes you would need to. And many more that you probably shouldn't do. PitStop Extreme is much more adept at manipulating PDF's (whether they are PDF/X or not) than PitStop is. But be prepared to pay for such power. There's limits to what PitStop can do at its price.
 
When I need to change a color, I make a new Illustrator document, place (link) my PDF into position on the page, select the PDF and flatten transparency with my custom preset.

This gives me the outlined type (so no type changes can be made) and objects I can change the color of. I know this isn't the way to do it (but if you think Acrobat is a joke like I do, and you believe it is being held back on purpose by Adobe, then screw it), but it works.

Also, when (I think) Matt said that the problem was ICC profiles causing black to get converted to four-color, this is why I turn my CMYK and Gray color management to Off (keeping the default profiles Adobe has to display CMYK and Gray). Adobe's "safe" CMYK workflow never was safe to me, so when testing on the first version it came with, I decided I'd rather turn CM for CMYK and Gray to Off to MAKE SURE no CMYK or K numbers were changing. And none ever do. Do this while using the North American defaults (if in North America), and you shouldn't have problems. Set press up to G7 and print those incoming SWOP separations with confidence.

Regards,

Don
 
wow thanks. I thought I was talking to myself there.
It's to late right now to go over all that but I will.
thanks for the input.
I appreciate all of your help.
 
I'm in Indd. cs4. Preflighting.
I have a ICC doc RGB and a sRGB IEC.
I've been converting from Indd with U.S. Web Coated (SWOP) v2
Is that the right move here? If they come out dark I take them into
PS
 
It's not wrong to convert on output from InDesign. You can use separation/output preview to see what the images will look like (if you have a color accurate display). You can also use separation output to turn off the black channel to see where you have 4 color blacks. You really may want to let Acrobat Pro do the RGB to CMYK conversion since it has an option to preserve blacks. I think the best way to do it is with callas pdfToolbox since it can recognize RGB grays and blacks and convert them to the correct space (device gray, separation black or k of CMYK). The way you would do it is to export a PDF (high quality print) and include all profiles. Then let pdfToolbox make the conversion. I can process a few jobs for you if you like to show you how it is done.
 
Thanks. I'm tided up for the day but I'll check into the pdf tool box. I take it thats a separate program?
 
It's a plug-in for Acrobat Pro or a standalone application. Both can be installed when running the installer. As a standalone editor it is very fast compared to Acrobat.
 

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