PDF's for clients with overprint preview

[prepressguru]

How can we correct overprint preview problems for clients? We send out a lot of PDF proofs which are low rez versions of our actual hi rez PDF to plate files. Some times there are overprints in these files when display incorrectly appear to have elements missing, but turning on the overprint preview corrects how it looks. Our clients see this and think the work is incorrect. But explaining to them it is setting in Acrobat resolves it. But having to do this just makes it seem we are in the wrong even if it is a technical issue. Is there a way to flatten the transparency/overprints so it is not necessary for the client to fiddle around with their software? I know this is no replacement for education but honesty the way print work moves these days clients just want to see the file correctly. I have played around with the flattener in Acrobat but the results look like the PDF with overprint preview off, which is incorrect. BTW we use Acrobat 7 and have 8 & 9 pro versions of course.

Thanks

[Hopkins Printing]

Is sending them a PDF with live transparency an option?

We used to struggle with this issue and like what you said, it gets old explaining it over and over while frustrating customers. Since then, we've upgraded our workflow system which handles native transparency with no pre-flattening required so we send them PDF files with native live transparency thus eliminating the need for overprint preview.

Kind regards,
Jon Morgan
Hopkins Printing

[toronar]

If your clients use Adobe Reader 9, send them PDF/X-1a or 3 or 4.
Reader 9's default setting is to activate overprint preview when displaying a PDF/X.

[Tech]

This old thread should help you.

Overprint preview in Acrobat-how to make a PDF view the same without it on?

[prepressguru]

Hi Guys, thanks for the suggestions.

Jon - We are moving towards using PDF engine or live transparency, currently we are wait for the latest patch for Printready so we can use Acrobat 9, which is very nice BTW.

Toronar - Not sure what version of acrobat our clients have, one is a huge corporate client and their software versions are not always the same in different departments. But so far PDF/X would force the setting to be on. I can recommend they try to update to version 9.

Tech - thanks for the link.. doesn't seem like there is a solution except for PDF/X

I think I will make screen captures... haha it has helped in the past.

[kyle]

Transparency and overprinting are two completely different things. Transparency effects involve blending the color values of an object and the objects underneath using one of a handful of formulas (multiply, screen, normal, difference, etc.) with an opacity variable, or using an alpha channel image. Overprinting objects are essentially opaque, but only affect the colorants that they contain, leaving the other colorants the same as they would be if the object were not there (e.g., 0/0/0/100 CMYK set to overprint leaves CMY unaffected, but 1/1/1/100 CMYK completely knocks out all CMY underneath). I think transparency effects should appear accurately going back to probably Reader 5 without having to change any default settings. I think overprinting preview may be on by default since reader 8 or 9, but maybe that's only for /X-1a.

The discrepancy between what the customer sees and what you will print is more of a problem when they don't realize anything is different. For example, if there is overprinting text that is white or some color other than black that they don't really want to overprint, or a black image set to overprint a spot color underneath that shouldn't - in these cases what they will see looks fine, whereas what you will print does not.

You might try printing to the printer "Adobe PDF..." from Acrobat to generate a new PDF, and use the "simulate overprint" option. If, for example, you have 0/0/0/50 CMYK text set to overprint 100/0/0/0, it will render the text as 100/0/0/50, changing the color of objects to achieve the same result as overprinting. I think Adobe may have included this for printing to desktop printers that normally ignore the overprinting attribute. If you want to give the customer the same PDF you are putting in the RIP and not a post-processsed one, and you are making the final PDF from Indesign, it also has the same option, but you won't be able to preserve transparency when you "print" instead of export.

Another possible workaround may be to change objects that overprint to knockout and change the blending mode to multiply, but that's certainly a time-consuming kludge, and would not yield identical results in many cases.

We use an Apogee RIP and Printdrive to store and manage the raster images and make proofs and plates from those images. I always make PDF proofs from there, because it is much safer than sending an abstract pre-RIP PDF, and every PDF page is a single flat CMYK image with spots converted to process - can't get much safer than that. Printdrive stores separate resources for each page because we use DQS (digital quick strip), so it can make a PDF page for every document page instead of an entire flat.

[prepressguru]

Hi Kyle

Thanks for the input. As you know Overprint and transparency effects are linked. Transparency realize on the use of overprinting for it to work in the world of printing.

Having the customer print off is an idea, but to go over this with them I am back to asking them to adjust settings. I just want to flatten the PDF so they see it without the overprint preview. So far the tools in Acrobat do not work for the result I want.

Good luck

[pcmodem]

prepressguru,

Transparency does not rely on overprinting to work. To prove this, Within InDesign:
Create a Frame and color the fill Cyan
Create another frame covering part of the Cyan frame, change the fill to Yellow and tell this to multiply
Create a third frame, again covering part of the Cyan frame, change the fill to Yellow, and tell this to Overprint.

Export this as a PDF and view in Acrobat 8 or lower and turn off "Overprint Preview" You will notice the transparency remains green where the 2 colors intersect but the overprint is yellow.

[Lukas Engqvist]

pcmodem. Transparency is allowed in certain versions of PDF, including the recent PDFx4 standard, the problem is that transparency is not "live" in PDFx1a, wich is based on PDF 1.3, or if you please Acrobat 4.

[pcmodem]

Lukas. I know that but I was trying to explain to prepressguru that transparency and overprint are two different animals. Overprint Preview does not turn on/off the ability to see transparency correctly, only overprints.

Transparency doesn't even exist in PDFx1a/PDF 1.3/Acrobat 4 (or below), it is flattened before getting created.