Pitstop versus Acrobat (Knockouts)

[JoshBright]

I work at a newspaper, and we ran into an issue today where a customer's ad did not print correctly. The issue was that a vector object didn't get knocked out correctly. There is this silhouette of a person on sorta jumping through a red ring on the bottom left, and the person isn't knocking out the ring as it should.

When I view this in Acrobat Pro 8, and use the separations preview, it shows the object (red ring) being knocked out correctly.
If I hide the silhouette of the person with Pitstop (version 7.5.1) , it shows the full ring without any of it being knocked out.

We mainly use the separations preview / overprint preview in Acrobat to look for overprint problems, so i'm trying to figure out what we can do to catch these issues going forward. Attached is the PDF that they sent us, unmodified. Can anyone help me with this?

Thanks!

 

[Greg_Firestone]

Hi Josh,

From what I can tell, there is no overprinting in the file. If any overprinting occurred, it might be a RIP setting or modified during pagination.

If I view the seps in Acrobat 9 Professional, the silhouette vector object is knocking out. I also verified this with FixMyPrintFile and it detected no overprinting in the file. You are using an older version of Pitstop (and Acrobat). What does pitstop say for the properties of the silhouette?

Regards,
Greg

 

[JoshBright]

---If I view the seps in Acrobat 9 Professional, the silhouette vector object is knocking out.

So that's sort of my problem. When I view the separations in Acrobat, the red ring is getting knocked out by the silhouette. When it prints, the red behind the silhouette is still there.

The only way that I can see this issue on screen is when I hide the object with Pitstop. When I do that, i show the red ring behind the silhouette, just like it printed.

I also tried Acrobat Pro 10, and it still shows the knockout happening. The only place I show it not knocking out is with Pitstop. Just to clarify I do want the red behind the silhouette to not print. Attached is an example of pitstop hiding versus acrobat separation preview. Hopefully this helps to illustrate the issue im trying to figure out.

Thanks for the help!

 

[Greg_Firestone]

Hi Josh,

I see what you're referring to - thanks for the pics. Can you provide more info on the workflow? Is the PDF placed into InDesign/Quark and then Exported as a PDF/EPS/PS? What happens if you view the paginated page in Acrobat/Pistop. Same results? If this is the case, I would lean towards it being a RIP setting. Your RIP can override knockout/overprint settings within a file.

Regards,
Greg

 

[DCurry]

The reason it shows the entire hoop when you hide the person is because you are hiding the shape that is supposed to knock out the hoop. It's not indicative of any overprint settings. The silo is set to knockout, as it should.

I suspect the problem lies in your RIP - either you have it set to overprint all black or, depending on your workflow, perhaps there is a Pitstop action to overprint black being performed somewhere in the workflow. Can you give us more info about the workflow?

Edit - looks like I was typing as Greg was posting the same idea!

 

[Greg_Firestone]

Edit - loks like I was typing as Greg was posting the same idea!

Great minds think alike

Greg

 

[DCurry]

Another question I have is what kind of proofing do you do? You should be able to catch this either on a hard proof or an onscreen preview of the ripped data.

 

[Colorblind]

As both Greg and Dan wrote, it's probably the black overprint policies in your rip or preflight workflow that are overriding what's in the file. I send ads to various newspapers myself and it sometimes happens that my black stuff (black fills, black lines, black text) gets overprinted/knockout when it wasn't in the file I supplied. Most of the time it happens with newspapers that have such systems as OneVision Asura -- I'm sure Greg knows about this one -- or Pitstop server and the way the black overprint policies are set.

 

[JoshBright]

Thanks for the replies!

I think you partly answered my question, I was somewhat under the assumption that when a PDF was created that had knockouts on it, that it actually removed what was there, instead of 'dynamically' figuring out what needed to be knocked out. I think you guys are right and I should look into the rest of the workflow (mainly the RIP) to see if there's something there (although I didn't see any settings for this on my RIP, although I didn't look into it too much).

The workflow we have here is a bit convoluted (although that seems to be the norm from what i've seen for the printing industry.. =).

1 - The ad in question was built by someone outside the company, so our first step is that we have someone who uses Pitstop to do some checking of the file.
2 - After everything is ok with the ad, it gets dropped into our newspaper system (Its called DTI), which is mainly just InDesign CS4 coupled with a database. The ad itself gets placed in an InDesign document (this is done by the system).
3 - Later, the page is output that has this ad on it, so the DTI system gets all the elements on the page and makes a PDF.
4 - After we get our final PDF, it goes to our RIP, which comes from Fusion Systems, but, at the core is a Harlequinn Rip (Version 7.2r0). The first step our RIP does is rasterize the page, which then goes to a folder, which then gets matched up with its other page.
If its the RIP's fault, I would think it would be at this stage here.

Also, as a heads up, we print 4 daily papers and 2 weekly papers here, and we use about.. 30 or so ads that are built by outside companies that get sent to us. Usually we do not have this issue, so, i'm curious as to why this ad has the issue, where-as normally we don't see this problem.

Does anyone happen to have any pointers on where I should look in a Harlequinn RIP to deal with this knockout issue? They don't seem to provide very good documentation (or we didn't get that documentation from Fusion Systems).

Thanks again for the replies!

 

[DCurry]

Before you check the RIP, check the PDF that is generated in step 3 just to make sure it didn't happen pre-RIP.

 

[JoshBright]

I forgot to mention about our soft proofing, we are able to look at the TIFF files before they get sent to our CTP machines using FirstProof Pro. So, technically we would be able to catch this, but, things do slip by here and there, and I like to try to be able to catch a lot of these issues before we get to that stage. To be honest, this probably has a lot to do with the people sending pages aren't quite as educated on all the nuances of how things print, which, is why I like to get things fixed before that..

 

[JoshBright]

The file that is created at step 3, shows pretty much what I am seeing with the ad itself. Traditionally, I would use either overprint preview or the separation preview to check using Acrobat. The PDF appears to be fine, I see the knockouts on the red ring, so, using just those tools, I would assume everything would be ok.

When I check the RIP'd page on step 4, is the first time I see the issue.

 

[JoshBright]

I think I found the area where I can change overprint settings in our Harlequinn RIP. Just not sure what they should be set at. Attached is a screenshot of the settings I found, can someone shed some light on if this looks correct or not?

Thanks again for the help!

 

[Greg_Firestone]

I believe it's the "Overprint 100% Black" which is changing the properties. Unfortunately the RIP only provides all or nothing settings. Ideally you'd want to overprint small black text/vector objects and knockout large text/vector objects. Just keep this in mind as you preflight incoming ads as it could impact your other advertisers. Maybe setup an Action in Pitstop. (I know how much colorblind loves this :=D).

For newsprint I generally overprint text 16pt or smaller, lines widths .25 or smaller, and fills .125" x .125" or smaller as long as the level of K is above 85%.

The Overprint Grays Option is only relevant if your sending PS or EPS to the RIP.

Regards,
Greg

 

[JoshBright]

Thanks Greg!! This option did the trick. Now, as you mention, I am worried what side effects this is going to have, but, at least I am getting somewhere.

 

[rich apollo]

Thanks Greg!! This option did the trick. Now, as you mention, I am worried what side effects this is going to have, but, at least I am getting somewhere.

If it were my cat to skin, I would turn off the "overprint 100% black" option AND the "override overprint mode in job" UNLESS you can verify what the "override overprint mode..." is doing. If it is setting the overprint mode of overprinting objects to OPM 1, then I'd leave it on.

I wouldn't worry too much about the side effects. If you don't force black to overprint, then the RIP will simply trap the black elements. Black not overprinting is not necessarily incorrect. It can be advantageous in some situations. The benefits of overprinting black type are that you have fewer elements for which misregistration is a concern, on a field of color the resulting black is more robust, and for versioning you limit the number of plates to be changed to a single black plate instead of all four plates.

I concern myself more with inappropriate overprint issues caused by blunt settings that force an overprint. I never engage the forced overprint setting in a RIP. In other words, I think you'll have greater success by leaving it turned off.

 

[caio]

---
when I hide the object with Pitstop

This is not an instrument for overprint check! The overprint or knock-out is an object's information. You need an instrument that onore this information like Acrobat Overprint preview. In Pitstop the instrument is in the inspector

 

[razvan]

My Brisque RIP does the same thing with black objects, even if they are not set to overprint in PDF or PS file. So i use two hotfolders: one with the riping option OVERPRINT set to ALL BLACKS and one with NONE.