Simulate Overprinting unchecked still overprints

For printer/rip devices that do not support PostScript Overprinting, this feature will create the same visual effect as a printer/rip which does process the overprint attributes. However if you printer/rip does actually support PostScript Overprinting, and has it enable by default, any PostScript Overprint commands in the file will be then honored. If you don't want the overprint, either disable the option at your printer/rip, or remove it from the file. The later can be done in the PDF using PitStop, or if you have the source files...in the authoring application.

You can easily preview to see if you have any overprint objects in the PDF. Simply choose Output Preview and select the Color Warnings option in the Preview area, then you can select the Show Overprinting checkbox to reveal any object with overprint settings on them.

Additionally...Simulating Overprinting will output the file as CMYK. Any spot colors assignments in the file will be converted.

Thank you for your response.

If I read it correctly, you're saying I have to change it in the printer's rip or actually tell the element to knockout in the native file.

I guess what you're saying is that the "Simulate Overprinting" option in the Advanced Print Window doesn't work. If it worked, I would be able to control it there, choosing to print either with overprinting simulated or not simulated.

Given that the "Simulate Overprinting" option implies a choice at the Advance Print Window, am I correct with my assumption that the "Simulate Overprinting" option doesn't work?

"Simulate Overprinting" works, but only as a way to emulate a true overprint for a printer/rip that does not understand or recognize overprint attributes. The only time "Simulate Overprinting" does anything is if there is a overprint attribute on an object(s) in the PDF.

I agree that the only time "Simulate Overprinting" does anything is if there is an overprint attribute on an object in the pdf.

I am talking about objects with an overprint attribute.

Since there is a "Simulate Overprinting" option for these objects, it stands to reason that if the box is UNchecked they should predictably NOT simulate their overprinting attribute. Otherwise, what is the point of having the option within the print dialogue box?

If there were no "Simulate Overprinting" option within Advanced Printing Options, then your answer would make sense, that the control would be at the rip or in the native file. But since the option is there, and does simulate overprinting when it's NOT checked, then something is wrong with that part of the application.

"Since there is a "Simulate Overprinting" option for these objects, it stands to reason that if the box is UNchecked they should predictably NOT simulate their overprinting attribute."

Is your printer a postscript printer, and does it support/honor overprint attributes? If yes, and there are overprint attributes in the PDF you're submitting, the printer is actually honoring and processing the overprint attributes as it's supposed to. The "Simulate Overprinting" check box is irrelevant in that scenario because your printer is actually taking care of processing the OP requests as it's supposed to, there is no need to simulate the effect prior to writing the PDF to PostScript.

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"Otherwise, what is the point of having the option within the print dialogue box?"

Again, the point of having this option is for printers that cannot process the overprint requests sent to it. For those print devices, the overprint effect must be simulated by Acrobat (and converted to CMYK) before it's written into a PDL (page description language...most common are PS or PCL) and sent over your network to the printer device. Namely these are older printers that are not PostScript level 3 devices...but not always.

Making sense now? If so, good. If not, well, either I'm missing your point, or you mine.

Oh, another comment about PDL's since i mentioned it in the prior post...
PDF is actually a PDL itself, but only relevant in a printing scenario if you can import it directly into a printer queue without need to perform a File > Print command where a print driver is invoked.

Thank you for your help with solving this problem.

After further experimentation I determined that it's an issue associated with the Color Profile used in the Advanced window of the Print Dialogue box in Acrobat.

I've always used a CMYK Color Profile since my files are all using CMYK color plus spot colors. In desperation I tried an RGB Color Profile and voila! the dieline color knocks out in my print out when I have Simulate Overprinting unchecked. Just like I wanted.

I think it's because the dieline color is a spot color and is from an Illustrator file that is set to RGB color mode to minimize the risk of the dieline color being interpreted as a CMYK color on output.

It definitely helped to dialogue with you in order to eliminate other possibilities for the issue.

Thanks again,

Tom

Might you know if overprinting support within a printer is common functionality? Or would it be present in more high end devices?

Thanks,

Rob

I use an HP 2600 for proofing and I wouldn't know how to find documentation written by HP that could address an issue as specific as overprinting support.

High end rips have total control of almost all printing variables within a document. Software that is functioning properly gives you options it can control and doesn't give you options beyond it's control. Since the print dialogue box in Acrobat is essentially Acrobat giving instructions to the rip in the HP via the driver then there is an implication that any available options in that dialogue box should be functional. Many functions pertaining to Post Script devices are visible but grayed out since the HP is not a Post Script printer. But since the "Simulate Overprinting" option IS available it should be safe to assume that by not checking it even elements set to overprint in Illustrator or InDesign will NOT simulate their overprinting characteristics when printing from the pdf file made from those elements.

Another interesting note is that if I print my pdf file containing overprinting elements from Acrobat to the HP using an RGB printing profile with "Simulate Overprinting" unchecked, the overprinting elements do not simulate their overprinting characteristics. This is what I expect. I can easily see this if I have a light colored element overprinting black. If instead I use a CMYK printing profile it will simulate the overprinting characteristic even with the "Simulate Overprinting" unchecked. And, if I go back to the RGB print profile AND I have the "Output Preview" or "Overprint Preview" options selected for viewing, these viewing options will override the unchecked "Simulate Overprinting" option. The overprinting will be simulated because of the active viewing options. I did not expect that they could influence printing.